Injuries of Jesse Lingard and Anthony Martial leave Ole Gunnar Solskjaer with problems to solve

Manchester United should be without Jesse Lingard and Anthony Martial against Chelsea Monday night in the fifth round of the FA Cup.

The duo has been a key figure in the Red Devils since the arrival of Ole Gunnar Solskjaer as acting leader.

Martial impressed on the left side of the attack, while the English international, Lingard, thrived at the forefront of a midfield diamond and also operated right when United came back at 4-3-3.

Both men took part in the defeat in the Champions League against Paris Saint-Germain midweek, but they both left the field injured, none of them appearing in the second half.

Martial had a recurrence of a problem at the groin that troubled him earlier in the season, while Lingard fell hugging his left hamstring.

Both men underwent scans for their respective injuries and both returned to United's training ground in Carrington on Friday to do some extra work with the club's physios.

The two players' injuries are not thought to be long-lasting, but both will be missed at Stamford Bridge and potentially at the club's next Premier League game against Liverpool on Feb. 25.

Solskjaer admitted Tuesday night that without the pair, United "had to find another way to play".

The Red Devils have seriously missed the pace and movement that both players bring to the formation, which allowed PSG to cancel United's offensive threat in the second half of the last 16 games; United made a shot on target all night.

That leaves United's interim leader with decisions to make as he seeks to recover from his first defeat since replacing Jose Mourinho.

Marcus Rashford will begin in West London, but the composition of the attack, apart from the English international, is much less certain.

Juan Mata and Alexis Sanchez were both ineffective against PSG after they came in, while Romelu Lukaku struggled in Fulham last week.

Solskjaer lamented Sanchez's posting after the match, saying: "I can not do anything against Alexis Sanchez.

"When he plays, he has to meet because we know that there is a quality player out there."

Sanchez has mostly been used since the left side of an offensive trio since he joined United, but the 30-year-old's move simply did not work.

For Solskjaer, there is also the question of training, United having used a diamond midfielder – Lingard in the lead – with a lot of effect under the Norwegian – especially during the victory in the fourth round at Arsenal and the 1-0 win against the Spurs at Wembley.

This training would allow Solskjaer to badociate Sanchez or Lukaku with Rashford in attack – he was using the Belgians and Chileans together in the UAE – with potentially Juan Mata or the Fred flop to replace Lingard at £ 52 million.

Lukaku's display in North London, when he recorded two helpers, combined with Sanchez's display in the middle of the week, probably outpaced him in the order hierarchical.

Fred, signed by Shakhtar Donestsk last summer, has been struggling for minutes since the departure of Mourinho and his inclusion would be a major shock.

But his strength could be an badet in the squad for United, against Chelsea midfielder Jorginho, crucial for the style of play of the Blues, but having been under pressure during their recent defeats.

All in all, if Lingard and Martial were in shape, United's starting lineup would be written by herself.

Instead, among injuries and players struggling for form, Solskjaer sees himself presenting his first big problem with tactics and personnel.