Mauricio Pochettino says Tottenham will have to wait until Monday for further news on Kieran Trippier's ankle injury.
The right-back collided with Alex Sandro just five minutes into Saturday's 2-0 pre-season friendly win over Juventus at Wembley but carried on, only to suffer a recurrence of the knock shortly before half-time.
With Kyle Walker recently joining Manchester City, the injury could leave Tottenham without an established right-back ahead of their first Premier League of the season at Newcastle, but Pochettino was unable to give a timeframe for Trippier's recovery.
He said, as quoted by Tottenham's website: "Kieran twisted his ankle and we need to wait until Monday to assess him."
Spurs' lack of transfer action has been criticised by supporters, with the club yet to make a signing with just one week to go before their first fixture of the season, but they may be forced into splashing out should Trippier's injury result in the England international missing a few weeks or months of the season.
Tottenham dealt with a similar full-back crisis last season when both Ben Davies and Danny Rose were unavailable for a trip to Chelsea, but this year could see the breakout of Kyle Walker-Peters should he be given the chance at right-back.
Trippier was widely expect to slot in at right-back following Walker's departure to City, with the former Burnley defender impressing towards the backend of last season with his crossing abilities as Walker's form dropped off.