Leroy Sane could be out for up to a month with an ankle injury sustained during Sunday's 2-0 FA Cup win at Cardiff City, according to Manchester City manager Pep Guardiola.
First-half goals from Kevin De Bruyne and Raheem Sterling gave the Premier League leaders a routine passage into the fifth round, but victory was soured after to Sane failed to emerge for the second half.
Sane scythed down
The Germany winger was scythed down by Joe Bennett, the Cardiff full-back who was booked at the time and later sent off for another ugly stoppage-time challenge on teenage substitute Brahim Diaz.
A prolonged absence for Sane would be a significant blow for Guardiola as he chases honours on multiple fronts.
"He will be out for a while. Maybe two or three weeks, one month," Guardiola told a post-match news conference, with Sane set to undergo and scan to determine the extent of the damage on Monday.
"We will see tomorrow exactly. It is his ankle."
Wednesday's Premier League game against West Brom would appear to be a no-go for the 22-year-old, who has 11 goals and 14 assists in all competitions this season, while the first-leg of the Champions League last-16 tie against Basel on February 13 may also come too soon.
City face Arsenal in the EFL Cup final at Wembley on February 25, launching a potentially pivotal seven-day period where they also travel to meet Arsene Wenger's men in the top flight before hosting Chelsea.