Hernanes is a doubt for Lazio's game against Cagliari this weekend, and could also miss the Coppa Italia final next weekend.
The Brazilian playmaker is struggling with a muscle problem picked up in training this week, and is likely to be rested for the match in Trieste on Sunday.
And the club's medical department are also concerned about the 27-year-old's fitness ahead of the cup final on May 26, according to Calcio News.
The player will undergo more tests at the weekend, but the Biancocelesti have released no official statement on the attacker's well-being.
Check out OLBG.com 's list of ££ Free Bets from UK bookmakers before placing your bets!