Manchester City left-back Benjamin Mendy is set to undergo tests by Pep Guardiola's trusted doctor amid concerns his knee injury is worse than first feared.
Mendy hobbled out of the action during the first half of City's 5-0 win over Crystal Palace on Saturday following an untidy challenge on Andros Townsend that saw the France international booked.
City boss Guardiola told a news conference ahead of Tuesday's Champions League Group F game against Shakhtar Donetsk that Mendy faced a late fitness test, but he missed out on the matchday squad and might be set for a significant time on the sidelines.
The former Monaco star will be assessed by Dr Ramon Cugat in Barcelona to determine whether he has sustained ligament damage.
City captain Vincent Kompany, David Silva, Ilkay Gundogan and Kevin De Bruyne have all been examined by orthopaedic surgeon Dr Cugat since Guardiola took charge at City last year.
England midfielder Fabian Delph will start on the left-hand side of the City defence in Mendy's absence against the Ukrainian champions, with Guardiola lacking senior cover at left-back after a significant squad overhaul during pre-season.
City won their Champions League opener at Feyenoord 4-0, while Shakhtar were victorious against Serie A high-flyers Napoli.
Guardiola's men travel to face Premier League champions Chelsea on Saturday, three points better off than Antonio Conte's side at the top of the table.
