NEW YORK -- Outfielder Brett Gardner underwent an MRI on Tuesday after experiencing a third setback in his recovery from a right elbow strain. Manager Joe Girardi was unsure of the results of the MRI when he met with the media before New York's game against the Blue Jays at Yankee Stadium.

Gardner took four at-bats in a simulated game Sunday, then felt soreness Tuesday and cancelled the plans to continue his rehab. He previously had a setback in early June, when the pain persisted a day after appearing in a game with Class A Charleston. He visited Dr. James Andrews shortly after and received a platelet-rich plasma and cortisone shot by Dr. Timothy Kremchek, the Reds' orthopedist.

Girardi did not dismiss the notion that Gardner could be on the roster in September and October solely for pinch-running and defensive purposes if he continues to experience setbacks swinging the bat.

Yankees not expecting Mo back this season

NEW YORK -- Joe Girardi and the Yankees are not changing their expectations for Mariano Rivera's return from surgery to repair a torn ACL in his right knee. A day after Rivera said in an interview with ESPN Radio's Michael Kay that his goal is to return this season, Girardi said that remains unlikely for the 42-year-old closer.

"He's trying," Girardi said, "and my anticipation is it's going to be very difficult because it's a short period of time [to recover], but we'll see what happens."

Girardi said Rivera would need a simulated Spring Training experience in order to be ready for the postseason. Rivera pitched in eight games this spring, five the year before that and six in 2010. Most Minor League seasons are over by September, making it even more difficult should Rivera recover in time from June 12 surgery.

Baseball's all-time saves leader tore his ACL on May 3 while shagging batting-practice fly balls in Kansas City, but delayed his surgery because of a blood clot in his right leg. The idea all along was that he would return next year for Spring Training.

Joba impressing in rehab with GCL Yankees

NEW YORK -- Joba Chamberlain continued to impress in his rehab with the GCL Yankees, retiring all three batters he faced Tuesday and striking out two.

The 26-year-old right-hander has struck out eight and is yet to allow a hit or walk in five innings over four rehab appearances since suffering an open dislocation of his right ankle in March. He also underwent Tommy John surgery last June.

Manager Joe Girardi said the Yankees still do not have an expectation of when he will return, but the plan is to continue to shorten Chamberlain's time between outings until he can pitch on consecutive days. Chamberlain began his rehab assignment July 10, and it can only last 30 days if there are no setbacks.

"We're encouraged," Girardi said, "and it seems like we're getting through this and it shouldn't be a real long time if everything goes according to plan."

Girardi said he would not hesitate to throw Chamberlain on consecutive days upon his return, but would more likely attempt to avoid situations where Chamberlain throws three times in four days.

Girardi would like to ease Chamberlain back into the bullpen, but the skipper trusts him against both right-handers and left-handers and said if he is throwing well and closer Rafael Soriano or setup man David Robertson need a day off, Chamberlain could see late-inning action.

Bombers bits

• The Yankees designated outfielder Darnell McDonald for assignment Tuesday to make room for starter CC Sabathia, who they activated from the 15-day disabled list. McDonald appeared in four games and went hitless in four at-bats since New York claimed him off waivers from the Red Sox.

• Girardi did not check with Alex Rodriguez before he penciled him into the fourth spot in the Yankees' lineup as the designated hitter Tuesday. Rodriguez complained of a stiff neck Monday and went 2-for-4 with a double and two runs as the DH. Girardi expects him to return to third base for the series finale Wednesday, when he plans to give Derek Jeter a half-day as the designated hitter.

• On this date in 1941, Joe DiMaggio's 56-game hitting streak was snapped with an 0-for-3 day against Cleveland. DiMaggio drew a walk and the Yankees won, 4-3, but Indians third baseman Ken Keltner made a pair of diving back-handed plays to keep DiMaggio hitless.