Strootman was substituted in the 34th minute at the Stadio Artemio Franchi - just his sixth Serie A appearance since returning from an anterior cruciate ligament injury, which he sustained in March last year.
But speaking after the match, Garcia claimed Strootman's situation was not "serious" and that the 24-year-old Dutchman had simply been withdrawn as a precaution.
"It doesn't look like Strootman's injury is serious but the doctor has seen him because his knee is still a delicate area," Roma's coach said.
"Kevin has had a tough time of it with injuries and we hope it's nothing serious."
Strootman has played 31 Serie A matches for Roma since joining from PSV Eindhoven before last season.
The Netherlands captain has been linked with a move to Manchester United under former national team coach Louis van Gaal, although this latest injury setback may make the Premier League club wary.
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