The Yankees have jumped out to a surprisingly strong start in the AL East, and they’ve done so while piecing together a rotation. Hiroki Kuroda and Brandon McCarthy are gone, CC Sabathia is a mere shadow of his former self, and Masahiro Tanaka has been battling arm soreness again, but the Yanks have found a way.

Now they’ll be without the services of Chase Whitley, who underwent Tommy John surgery this week and will miss the remainder of the season. Whitley had looked pretty good in early action, but after going under the knife, he’ll rehab and try to return late next year.

Replacing him in the rotation is Chris Capuano, who performed well enough over 12 starts for New York last year with a 4.25 ERA and 55-to-19 K/BB ratio in 65 innings. Despite a rocky first outing last Sunday, the 36-year-old southpaw holds relevance in AL-only leagues.

* On the bright side, the Yankees’ beleaguered rotation might get a boost soon. Tanaka threw a problem-free bullpen session on Monday and made a Triple-A rehab start on Thursday, throwing three scoreless frames. He’s expected to need a couple more starts in the minors before being activated, but hopefully he’ll be back in early June.

* It’s been a long time coming, but on Friday the Red Sox finally called up their expensive Cuban import, Rusney Castillo. The outfielder had debuted in the majors late last season, less than a month after inking a $72 million contract with Boston, but opened the 2015 campaign in Triple-A, where he was hitting .293/.341/.440 prior to his promotion.

Offering solid speed and pop, Castillo has a fantasy-friendly skill set, and considering his success in last September’s cup of coffee (he batted .333 with a 928 OPS) he seems like a good bet to smoothly transition to the majors.

He started in right field on Friday night in his season debut, and figures to be a staple there going forward.

* Scooter Gennett established himself as one of the better young second basemen in the National League by hitting .300/.331/.449 in 206 games between 2013 and 2014, but he got off to a dreadful start this year and was optioned to Triple-A on Monday with a 407 OPS. The 25-year-old’s poor plate discipline has always been somewhat of a red flag, and was particularly problematic this year as he struck out 19 times with only two walks before the demotion.

If he can improve his strike zone control in the minors, Gennett figures to return soon because Milwaukee can’t be too amped about starting Hector Gomez or Elian Herrera at second.

* After watching Victor Martinez limp around on a bad knee and struggle to the tune of a 578 OPS, the Tigers finally took action on Tuesday, placing him on the DL and replacing him on the roster with outfielder Tyler Collins. It’s tough to say how long V-Mart will be sidelined but this knee has been a problem for a while, so Detroit will want to make sure it’s all cleared up before bringing him back. Collins, who’s started a couple times at DH since being called up, is a decent hitter and might hit a few over the fence, but his fantasy value is marginal at this point.

* Hyun-Jin Ryu has been one of the most quietly consistent starters in the National League over the last two years, but we won’t be seeing him in 2015. He’s been out since mid-March due to shoulder soreness, and opted for season-ending surgery to repair a torn labrum this week. Carlos Frias and Mike Bolsinger might both be sticking around for a while in the Dodgers rotation.

* The Mariners acquired catcher Welington Castillo from the Cubs on Tuesday in exchange for reliever Yoervis Medina. It was a positive development for Castillo, who was buried on the depth chart in Chicago and figures to see a playing time boost as Mike Zunino‘s primary backup in Seattle. Castillo has shown some offensive ability in the past, and Zunino is batting just .175, so the opportunity is there for an increased role.

* Corey Dickerson enjoyed a breakout season in Colorado last year, and was off to another excellent start here in 2015, but this week he landed on the disabled list with the dreaded plantar fasciitis. This is a very pesky injury that can be tough to shake, but hopefully some time off his feet will help the outfielder mend.

The good news is that Dickerson has been highly productive this year even while playing through the pain, so even if the problem isn’t completely solved by a few weeks off (it probably won’t be), he still has a chance to come back and do some damage.

* I’ll never forget the seemingly innocuous bump to the head that Justin Morneau sustained when trying to break up a double play in Toronto back in July of 2010. The Twins first baseman was on an MVP pace, but the concussion he sustained on the play ended his season, with lingering effects taking a substantial toll on his playing time and performance in the years that followed. As such, it was gut-wrenching to see Morneau suffer another concussion while diving for a ball last weekend, and even worse (though not surprising) to learn that he wasn’t going to be ready to return after his 7-day DL stint.

Rockies manager Walt Weiss said Thursday that Morneau will need “at least a few more days” to recover, and considering the history here, the “at least” part should be emphasized.

* Addison Reed was removed from the closer role in Arizona last week, and while manager Chip Hale has stated that he plans to play match-ups, and that’s how what we’ve seen. This past week, Enrique Burgos drew two save chances and Brad Ziegler got another. It’s probably best to avoid this situation, but if you’re desperate for saves, I’d target Ziegler. Burgos’ shaky control makes him an iffy proposition in the ninth.

* Jaime Garcia made his long-awaited season debut on Thursday, holding the Mets to two runs over seven innings in New York. We’d like to believe that Garcia is finally free of the shoulder issues that have plagued him over the past couple years and kept him out of action for the first seven weeks of this season. When on the mound, the 28-year-old has always been effective, but he’s a risky bet.

* A week ago, it appeared certain that Rays starter Drew Smyly was headed for season-ending surgery on his ailing shoulder, but this week the club determined that his tear is not significant enough to require surgery so he is expected rehab and to return later this year, though probably not until August at least.

* It’s been a tough, tough season for Oakland outfielder Coco Crisp. An elbow injury kept him out for the first month, and after returning in early May he looked horrible, collecting just two singles in 45 at-bats. It turns out that the likely reason is a neck problem that’s been bothering him, and after visiting a specialist this week, Crisp reported that he received “disheartening news,” and the next day he landed on the disabled list with compressed discs. Things are looking gloomy for the 35-year-old.

* It’s not often you see two managers fired within the first two months of the season, but Mike Redmond followed Ron Roenicke‘s footsteps this week when he was dismissed by the Marlins. Stepping in for Miami is GM Dan Jennings, who has zero professional managerial experience. This should be interesting.