Nationals reliever Ryan Mattheus' broken hand will force him to miss 4-6 weeks, the Washington Times reports.

Mattheus slammed his right (pitching) hand into his locker after Sunday's game against San Diego. The fracture will not require surgery but because he won't be able to move his pitching hand, the work required to get his arm back in shape will force him to miss at least a month.

Royals starter Danny Duffy will throw 60 pitches Sunday at Double-A Northwest Arkansas in his first rehab start since Tommy John surgery last season, the Kansas City Star reports.

Duffy's return comes a bit earlier than expected, as the one-year anniversary of his surgery approaches June 13. The club was hoping for Duffy to go on a rehab assignment around that date, so his progress should be seen as positive. He will likely use most of the 30 days allowed for pitcher rehab assignments before he returns to the major leagues.

The Blue Jays have shifted pitcher J.A. Happ to the 60-day disabled list to open the roster for Friday's starter, Sean Nolin, the club announced.

Happ suffered a nasty head injury in his last start May 7 against Tampa Bay, but his knee, tweaked as a result of the subsequent fall, continues to bother him. Happ won't be available until mid-July as a result of the move.

The Blue Jays have called up prospect starter Sean Nolin from Triple-A Buffalo, the club announced Friday. He will start Friday's series opener against Baltimore.

Nolin was scratched from Thursday's start at Buffalo in order to make Friday's game. The Blue Jays placed Darren Oliver on the 15-day disabled list and moved J.A. Happ to the 60-day disabled list to make room on the roster.

Nolin allowed just three runs (two earned) over 15 1/3 innings in his first three starts at Buffalo. He struck out 16 against just five walks. 

The Blue Jays have placed lefty reliever Darren Oliver on the 15-day disabled list with a left shoulder strain, the club announced Friday.

Oliver, 42, accrued a 3.18 ERA and 1.8 K/BB over 17 innings in the Blue Jays' bullpen. Oliver's disabled list stint can be backdated to May 18, and he's eligible to return by June 2.

Cardinals starter Jake Westbrook hit a snag in rehab from an elbow injury earlier this week, but he does not appear to be seriously hurt, the St. Louis Post-Dispatch reports.

Westbrook felt right elbow pain during a bullpen session Wednesday. The issue will keep him from coming back next week as originally planned, but it appears the issue will only push him back about a week at this point. Westbrook compiled a 1.62 ERA in 39 innings prior to the injury.

The Indians are considering recalling pitcher Carlos Carrasco, the Cleveland Plain Dealer reports.

Carrasco has been dominant at Triple-A Columbus, as he owns a 1.36 ERA and 4.6 K/BB over seven starts (39 2/3 innings). The only hitch for the Indians is the eight-game suspension he was tagged with in April for hitting Kevin Youkilis with a pitch in his only major-league start of the year.

Carrasco has appealed the suspension. He may be able to come up for a start while MLB rules on the appeal -- likely July 10 against Toronto -- and then serve his appeal around the All-Star break, giving the Indians a chance to rearrange their rotation in such a way that Carrasco isn't just dead weight on the 25-man roster. 

However they decide to solve it, the Indians have been impressed with Carrasco's performance in the minor leagues, and they expect to find some way to bring him up this season.

Tigers third baseman Miguel Cabrera continued his torrid pace Thursday, homering for the fourth straight game. He has six home runs and 13 RBI over his last four games while going 9 for 15 with five walks.

Cabrera's .391 batting average and .701 slugging percentage lead all major-league players, and his .467 on-base percentage ranks second to Joey Votto. He's been hitless just twice in his last 34 games. He's the early favorite for 2013 AL MVP.

Twins left fielder Josh Willingham hit two home runs against the Tigers Thursday, but it wasn't enough as Minnesota lost 7-6. Willingham went 2 for 5 with four RBI, his first with four-RBI game this season.

Willingham has hit .212/.368/.453 with eight home runs and 23 RBI in 171 plate appearances. His multi-homer performance was his first since July 24.

Returning from a bruised hip, Royals catcher Salvador Perez went 3 for 4 with an RBI before being removed for a pinch runner in the ninth inning of a 5-4 loss to the Angels Thursday. It was Perez's eighth multi-hit game in May, raising his season line to .320/.336/.422 with a home run in 152 plate appearances.