Italy's medical staff - and Nicolo Zaniolo himself - are concerned about a new knee injury sustained in the win over the Netherlands.
Roma and Italy midfielder Nicolo Zaniolo has suffered a serious-looking knee injury, according to the Azzurri's doctor.
Zaniolo limped from the pitch in obvious discomfort after an innocuous collision with Donny van de Beek in Italy's 1-0 win over the Netherlands in Amsterdam on Monday.
The 21-year-old had only recently recovered from surgery on an anterior cruciate ligament tear sustained in January, making eight appearances for Roma in the closing weeks of the prolonged Serie A season.
Italy doctor Andrea Ferretti says the player looks to have suffered "major" damage to his left knee - not the one he injured back in January.
"It looks like a major knee sprain," Ferretti said to Rai Sport. "It's difficult to draw comparisons with the other knee because that's already been operated on.
"It's a sprain of some importance. He's coming out of that long rehabilitation process for the other cruciate and he's obviously worried, as we are, too."
Italy head coach Roberto Mancini said he was sorry for Zaniolo, adding: "I hope it's nothing serious. We'll know more tomorrow."
A header from Nicolo Barella secured Italy's win over the Netherlands and moved them top of Group A1 in the Nations League.