Anthony Martial and Jesse Lingard have been ruled out for two to three weeks and will miss Manchester United's games against Chelsea and Liverpool.
Lingard pulled up shortly before half-time in the first leg of the last-16 tie against Paris Saint-Germain at Old Trafford with what appeared to be a hamstring injury.
Martial was injured earlier in the game and played on until the interval but did not reappear for the second half.
"I think they will be out for two to three weeks looking at it now," Solskjaer said in his press conference ahead of the FA Cup fifth-round tie with Chelsea.
A three-week absence would see both players miss the Premier League game at home to Liverpool next Sunday, live on Sky Sports, and could even see both sit out the return leg against PSG on March 6.