Bohm singled to left-center in the second inning with two outs and tried to stretch his hit into a double. He dove into second, immediately began to favor his left hand and appeared to say "it's broken'' to someone on the field.
"X-rays were negative,'' interim manager Rob Thomson said after the game. "They popped it back out and he'll play to tolerance, but we don't know what the move is yet.''
Bohm will sit out Tuesday and Wednesday at Toronto because he is not vaccinated against COVID-19. J.T. Realmuto, Aaron Nola and Kyle Gibson will also miss the series due to Canadian restrictions on unvaccinated travelers.
Bohm was called out on the play, but the Phillies challenged the call. Umpires ruled that second baseman Nolan Gorman got the tag down.
The 25-year-old third-year player has a hit in 14 of his last 15 games. He was replaced by Yairo Munoz.
The Phillies lost to the Cardinals 6-1, the third time Philadelphia has lost consecutive games since the start of June.
The Associated Press contributed to this report.