Over the past several weeks, the Rotoworld staff has been highlighting players whose fantasy value is on the rise headed into the 2015 season. We’ve been breaking them down by division. The National League East, National League Central, National League West, American League East and American League Central have already been tackled. Now we finish things off with the American League West …

For all the latest Hot Stove news, keep it locked all offseason long on Rotoworld’s player news page. You can also follow @Rotoworld_BB and @RyanPBoyer on Twitter.

Garrett Richards, SP, Angels

Richards showed flashes of upside prior to last season, but he really put it all together in 2014. The former sandwich round pick put up a 2.61 ERA in his 26 starts for the Angels to go along with a 1.04 WHIP and 164/51 K/BB ratio across 168 2/3 innings. Unfortunately, Richards’ season ended prematurely with a torn patellar tendon in his left knee. The good news is that he’s been cleared to begin his offseason throwing program and is expected to be ready to roll by Opening Day.

Richards is essentially a two-pitch pitcher, but man, are they an impressive pair of offerings. The average velocity of the right-hander’s fastball last season, according to Fangraphs.com, was 96.3 mph. And not only does the pitch have plenty of zip, it also has good sink, which has helped lead to a 52.3% groundball rate and just five homers allowed in 2014. Richards also possesses a wipeout slider that often looks unhittable. The breakout was real, folks.

George Springer, OF, Astros

Fantasy owners had been salivating over Springer’s potential long before he was promoted in mid-April last season. That tends to happen with a guy who hit 65 homers and stole 87 bases over 287 minor league games while batting .302/.398/.562. Springer started off slowly with the Astros and had his season end early due to a quad ailment, but in between that he slugged 20 homers and drove in 51 runs over 78 contests.

Springer isn’t without his warts. He swung and missed a lot in the minors and then struck out a whopping 114 times over 345 plate appearances with the big club. Chances are he’s probably never going to hit for a high average and almost certainly won’t do so right away. Springer also stole a disappointing five bases during his time in the majors. That part of his game should pick up, though, and the power is undeniable. This is one of the best young power/speed combos in the game.

Kole Calhoun, OF, Angels

Calhoun was the leadoff hitter from Day 1 last season for an Angels team that led all of baseball in runs scored. The 27-year-old certainly did his part, sporting a .272/.325/.450 batting line with 17 homers, 58 RBI, 90 runs scored and five stolen bases. Calhoun’s counting stats would have been even better if not for a severely sprained ankle that cost him five weeks of action.

There could be even more in the tank with Calhoun. This is a guy who put up a robust .320/.403/.545 batting line during his time in the minors, so improvement from a batting average perspective is a reasonable expectation. Calhoun also stole 45 bases while on the farm, so it wouldn’t be a surprise if he chips in with a few more steals in 2015. The Halos’ outfielder doesn’t really stand out in one area but offers nice across-the-board production.

Dallas Keuchel, SP, Astros

Keuchel was undoubtedly one of baseball’s biggest surprises last season. Entering the campaign with a career 5.20 ERA over his first 239 major league innings, Keuchel went on to post a 2.93 mark over 29 starts for the Astros. The left-hander paired the snazzy ERA with a solid 1.18 WHIP and 146 strikeouts across an even 200 innings.

The southpaw isn’t going to overpower batters, as his fastball often struggles to crack 90 mph. What Keuchel does do is pound the strike zone and induce a ton of groundballs, with his ridiculous 63.5% groundball rate in 2014 easily leading all of baseball. Keuchel isn’t going to strike out too many batters and his ERA will surely jump back up over the 3.00 mark in 2015, but the lefty should be a solid fantasy option again.

Matt Shoemaker, SP, Angels

Shoemaker’s ascension last season was arguably even more surprising than Keuchel’s. After all, this was a hurler who put up a pedestrian 4.52 ERA in the minors and a 6.31 mark in his first five Triple-A starts last year before the Angels promoted him in mid-May. So what did Shoemaker do for the Halos? Oh, just go 16-4 while posting a 3.04 ERA and 124/24 K/BB ratio over 136 innings on his way to being runner-up in the American League Rookie of the Year voting.

So can we expect Shoemaker to keep it up? He has a few things going for him, with a nasty splitter and the ability to throw strikes consistently. He’s also, as a flyball pitcher, helped out greatly by Angel Stadium, which should keep his home run total at a reasonable level. Shoemaker almost surely isn’t going to hold an ERA around 3.00 again in 2015, but there’s a lot for fantasy owners to like about him. Some guys just take a bit longer to find themselves, and that appears to be the case here.

Collin McHugh, SP, Astros

Well, we might as well keep the surprise breakout train rolling along. McHugh was always considered a middling prospect and arrived in his third organization in six months when the Astros claimed him off waivers last December. Promoted in late April, McHugh struck out 12 batters over 6 2/3 shutout frames in his first start with Houston and never looked back. The 27-year-old finished with an improbable 2.73 ERA and 157/41 K/BB ratio over 154 2/3 innings.

To be fair to McHugh, he did post a 636/200 K/BB ratio over 657 2/3 innings in the minors, so perhaps we shouldn’t be too surprised about the number of swings and misses he got last season. He also saw his average fastball velocity jump up over a full mph to 91.6 mph, according to Fangraphs.com, and his curveball has turned into quite a weapon for him. The real challenge now will be repeating his success, but there’s no doubt McHugh’s trajectory is pointing in the right direction.

Sean Doolittle, RP, Athletics

It wasn’t that long ago Doolittle was a first baseman in the minors for the A’s, which makes his meteoric rise to one of the best relievers in the game all the more stunning. The left-hander has always posted impressive K/BB ratios since he converted to pitching, but he took it to another level in 2014 with a ridiculous 89/8 K/BB ratio across 62 2/3 innings. With other A’s relievers either ineffective or injured, Doolittle eventually got a shot to close and converted 22-of-26 chances.

There’s little doubting Doolittle’s ability to maintain success in the ninth inning. We’re talking about a pitcher with a career 2.97 ERA and 2.20 FIP who strikes out over a batter per inning and doesn’t walk anyone. Doolittle’s one bugaboo is that he gives up a ton of flyballs, but O.co Coliseum and the A’s strong outfield defense helps negate that. This is an elite closer.

Honorable Mentions

Sonny Gray, SP, Athletics

Gray was impressive in his first taste of the majors in 2013, and he kept it up in his first full season in 2014. The former first-round pick put up a 3.08 ERA while striking out 183 over 219 frames for the A’s, picking up a couple shutouts along the way. Gray did appear to tire a bit with the increased workload, holding a 4.07 ERA over his final 11 starts, but he should be better equipped to handle the innings in 2015. The 25-year-old is in a favorable home park and will serve as the A’s No. 1 starter following the trade of Jeff Samardzija.

Chris Carter, DH, Astros

One of the game’s notoriously streaky hitters, Carter was pretty terrible for much of the 2014 season. However, he also went on a two-month binge that saw him bat .296/.355/.678 with a whopping 23 home runs over 52 games. All told, the soon-to-be 28-year-old slugged 37 homers (a total bested only by Nelson Cruz) while also hitting just .227 with a .308 on-base percentage. Also worth noting is that Carter will only be DH-eligible in many leagues in 2015. The holes in his game are obvious, but Carter is also capable of carrying a squad when he’s hot.

Roenis Elias, SP, Mariners

A Cuban defector, Elias pitched well at Double-A for the Mariners in 2013, posting a 3.18 ERA while striking out nearly a batter per inning, but it was still a surprise to see him break spring training as a member of the big league rotation. The southpaw more than held his own, putting up a 3.85 ERA and 143/64 K/BB ratio across 163 2/3 innings. Elias’ fastball sits in the low 90s, which is plenty enough for a lefty, and he’s got a superb curveball. One red flag is that he ended last season with a strained left flexor bundle in his elbow, but he didn’t need surgery and the M’s don’t seem overly concerned about it being a long-term issue.

C.J. Cron, 1B/DH, Angels

A former first-round pick, Cron was promoted by the Angels in early May and he got off to a fine start, batting .301/.328/.577 with eight longballs over his first 40 games. His playing time tailed off after that and he hit just .210/.248/.319 the rest of the way,  but Cron made good enough of a first impression that he’s currently in line to be the team’s Opening Day designated hitter in 2015. Cron lacks plate discipline, so hitting for average probably isn’t in the cards. His power is real, though, making him a decent late-round option for a category that’s increasingly harder to find.

Robinson Chirinos, C, Rangers

Chirinos flashed some upside with the bat in the minors, most notably batting .312 with 29 homers over a two-year stretch in the Cubs’ organization from 2009-10. However, he never got an extended look in the majors until last season with the Rangers, and he responded with 13 dingers over 338 plate appearances. He hit just .239/.290/.415 overall, as Chirinos is far from a well-rounded product. He does have some juice in his bat, though, and is playing in a nice hitter’s park. The Rangers could wind up upgrading at catcher this winter, but as it stands right now Chirinos looks to be their primary option behind the plate.