Pau Gasol will undergo an MRI scan after missing the end of the Chicago Bulls' win over the Cleveland Cavaliers in game three of their playoff series.
The center managed just 22 minutes and six points before having to exit the 99-96 win, which puts the Bulls 2-1 up in their Eastern Conference semi-final.
He told ESPN: "[The hamstring is] sore. It tightened up already in game two. Today, it started off well, but a couple minutes into the game, it started tightening up again.
"I just tried to play through it as much as I could, but in the second half, third quarter it got worse, so I couldn't sprint. I definitely couldn't sprint.
"We got to a point where I couldn't really run well, either. So just had to get out of the game, and we'll evaluate it tomorrow."
Game four of the series takes place tomorrow.
