Escobar was listed to play shortstop and hit seventh against the A's. He was removed less than 90 minutes before first pitch and replaced by veteran Omar Vizquel.
The 29-year-old Escobar has been mentioned in trade rumors for the past week but Wednesday's decision had nothing to do with a potential deal.
"He felt some tightness in his lower back during batting practice," Blue Jays manager John Farrell said after his club's 16-0 loss to Oakland. "Precautionary, made the move to withhold him, didn't want to push it.
"Whether or not he's available tomorrow, we'll check and see in the morning when he comes in but that was the reason for tonight."
Escobar is guaranteed $5 million in 2013 and the club also has a pair of team options after that season valued at an additional $10 million. The Cuban native could potentially be available prior to the non-waiver Trade Deadline with prospect Adeiny Hechavarria waiting in the wings at Triple-A Las Vegas.
Through 93 games this season, Escobar is hitting .255 with six home runs and 34 RBIs. That's a dropoff from last year, when he hit .290 with a .369 on-base percentage and 38 extra-base hits.