Maddon said Aybar's hamstring was tweaked in a play at the plate in Wednesday's 7-1 loss to Seattle. Aybar was trying to score on Jason Bartlett's base hit to left field, but was tagged out by Kenji Johjima.
"He's been getting all the treatments, doing all the right things, he's been working his butt off to stay out there," Maddon said. "It's just that play took a little bit out of him."
Aybar was 3-for-4 Wednesday, including two doubles, and is batting .292 with a .500 slugging percentage. The switch-hitter's bat is direly needed for a Rays team batting .167 in the past four games.
Fortunately, with eight players already on the 15-day disabled list, Aybar is not expected to be No. 9. Maddon said Aybar would be available to pinch-hit in Thursday's game if needed, and the decision to back off was done to prevent any serious damage.
"Those are the kind of things that really mess you up," Maddon said. "He's been sore the last couple days and he's been playing through the cold weather ... just extended on that play and he just felt it a little bit."
Although temporary, the setback joins a long list of negatives piling on the club during its four-game skid.
"Right now we are way up there on ice -- ice and injections," Maddon said.
Recent news on the Rays' crowded DL is Scott Kazmir's second live bullpen session, scheduled for Friday afternoon. Maddon admittedly misspoke Wednesday when he said the session would occur Saturday. Kazmir is expected to throw about 10 pitches more than his session on Tuesday, which was in the 70s, and included 42 to live batters. The left-hander has been sidelined since Feb. 25 with a left elbow strain.
The next step for Kazmir will be to pitch in an extended Spring Training game at the Rays' Minor League Complex, which is what Kurt Birkins is slated to do Friday. Birkins, who has been sidelined with left elbow neuritis, will throw one inning in a controlled situation.
The latest of the Rays arm woes, Matt Garza, has been resting since leaving Tuesday's game with radial nerve irritation. Garza, who is also on the DL, is tentatively scheduled for a soft toss session on Saturday.
Brittany Ghiroli is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.