Szczur began to inch off third base as David Ross attempted to steal second in the fifth inning of the Cubs' 7-2 win. When Ross got caught in a rundown, Szczur headed home, but as the throw came in, he stopped and then started again, injuring the hamstring. He eventually scored when Josh Harrison's throw sailed over the catcher's head.
"When I pushed off, I felt something a little bit, but I was able to run home, so I don't think it's anything severe," Szczur said after the game.
Manager Joe Maddon said he and team president Theo Epstein will discuss options in case Szczur has to go on the disabled list. Szczur was asked if he might need some time to mend the hamstring.
"I hope not," he said.
Szczur is off to a good start in a backup role for the Cubs. He has two home runs and 10 RBIs in limited playing time this season.