Gibbons wasn't sure how much time either player might miss, though McDonald's ankle injury appears to be the more severe of the two. McDonald, who could potentially land on the 15-day DL, replaced Eckstein in the fifth inning and was forced from the game one frame later.
In the sixth, Gabe Gross sent a 3-1 pitch bouncing toward the hole between shortstop and third base, where McDonald glided to his right and made a sliding catch to snare the ball. McDonald rose slightly, but winced in pain and fell back to the turf, clutching the back of his right ankle.
Toronto's players gathered around McDonald, while Blue Jays head trainer George Poulis and Gibbons made their way onto the field. Poulis eventually helped McDonald position himself on a medical cart, and the crowd reacted with a round of cheers for the backup infielder.
"Mac's was scary," Blue Jays center fielder Vernon Wells said. "Obviously, we were all on the field and on turf you never know what can happen. I was happy it wasn't his Achilles' [tendon]. When you have sudden movements and then you go down, that's the first thing you think of."
Lyle Overbay said he talked to McDonald after the game, and the shortstop indicated that the ankle wasn't broken.
"I know that he rolled his ankle," Overbay said. "When you go down like that, it's something that could be serious. It sounds like it's not as serious as it looked. So that's good news."
McDonald may have sprained the ankle, though Gibbons said the Blue Jays would have a clearer indication of the extent of the injury on Wednesday. Gibbons also wouldn't speculate on the seriousness of Eckstein's injury, which was suffered on a dive during the third inning.
"It's hard to say," Gibbons said. "Where Dave's is, in the hip flexor, that can nag you pretty good. Johnny's is down by the ankle. Those can give you a lot of problems, too. I wouldn't expect to see either one for a few days anyway."
Eckstein tried to catch up with a popup off the bat of the Rays' Dioner Navarro, racing to his right into left field and diving in an attempt to catch the ball. Eckstein said he felt some discomfort shortly after the play, but he remained in the game until the fifth inning.
"When I went to dive for the ball, when I went to plant, that's when I did it," Eckstein said. "I tried to stay out there and, when I was running around the bases, I really couldn't run at all. I was running as fast as I could and it wasn't going that good.
"You don't want to come out of the game, but you don't want to be stupid."
Gibbons said that utility man Marco Scutato, who took over for McDonald in the sixth, will serve as the temporary starting shortstop. Scutaro -- acquired from Oakland via trade over the offseason -- has appeared in 216 games at shortstop in his career.
If either McDonald or Eckstein land on the DL, shortstop Jorge Velandia is one potential candidate to earn a promotion from Triple-A Syracuse.
Velandia, 33, has had big league stints with the Rays, Mets, A's and Padres in parts of seven seasons, dating back to 1997. This season, Velandia was hitting .287 with three home runs and 12 RBIs through 28 games with Syracuse.