Injured Kompany out for two weeks
The Belgian international defender limped off early in the first leg of the last 16 tie in Lisbon which City lost 1-0.
City said Kompany will miss the Premier League game at Swansea City on Sunday, the return leg against Sporting and the home clash with Chelsea on March 21 unless he recovered more quickly than anticipated.
"We have to wait one or two days to know the exact extent of his injury, but it is a problem with his calf," coach Roberto Mancini said on City's website.
"I hope to have Kompany back in 10 days or two weeks, but we have other solutions."