With Zlatan Ibrahimovic out for a month and Romelu Lukaku expected to miss the next two games after suffering a head injury against Southampton, Jose Mourinho has been left with Marcus Rashford and Anthony Martial as his options at centre-forward.

A section of United supporters will tell you that having the pace of Rashford or Martial up front is no bad thing. They are likely to find out on Monday at Goodison Park whether they are right.

It is a blow for Mourinho. In his mind, he has two strikers in his squad -- Ibrahimovic and Lukaku -- and both are now sidelined with injury. He already feels that his squad is stretched to its limit, and losing two more players -- and in the same position -- presents a significant problem.

"Zlatan is one month out," he said after the 0-0 draw Saturday at Old Trafford, United's third in a row in the Premier League.

"I don't know about Lukaku. Of course, you miss your striker and your target man. You only have two attacking players on the bench, Rashford and Martial, and you lose one of them immediately.

"I wanted a third change late in the game, and I didn't have a third attacking player, so that's difficult."

Mourinho has lost options. The inconvenient truth, though, is that neither Lukaku nor Ibrahimovic has been playing well.

Lukaku's United career started with 11 goals in his first 10 games. Since then, he has scored just four times in 20 games.

He lasted just eight minutes against Southampton before being injured, but the Belgian had already managed to miss one golden chance after heading Juan Mata's early cross over the bar.

Ibrahimovic, meanwhile, has not looked like the same player since returning from a serious knee injury in October. He has scored once -- a good free kick against Bristol City -- but has rarely looked like adding to that tally.s

Mourinho accepted at his news conference on Friday that the pair are "not in a good moment."

Lukaku, he said, needed a rest after playing every minute of the first 20 Premier League games of the season. It is unlikely that he would have gotten one had he not suffered an injury.

Rashford and Martial offer something different. Instead of trying to hold up the ball and thriving on crosses into the box, both prefer to play on the shoulder of the last defender.

When it works, it can make United look faster and more fluid. There were flashes of it against Southampton. Rashford and Jesse Lingard linked up well in the first half. Henrikh Mkhitaryan, making his first start since Nov. 5, joined in occasionally, but ultimately, he didn't do enough to convince Mourinho he should start again at Everton on New Year's Day.

Rashford might have had a goal, had he been more ruthless in the box. That will have to improve if he is chosen to lead the line in Lukaku's absence.

It was Rashford whom Mourinho turned to at the end of last season, when Ibrahimovic's campaign was ended by a knee ligament injury. But in five starts as United's central striker in April and May, the 20-year-old scored just once.

His form in front of goal has improved this season, and he already has nine, just two fewer than he managed in the whole of the previous campaign.

For Rashford, the injuries to Lukaku and Ibrahimovic present a chance for an audition. He wants to play as a striker but, under Mourinho, has often found himself out wide.

Had Lukaku and Ibrahimovic stayed fit, it is likely he would have stayed there. But if he can go on a goal-scoring run at centre-forward, he might convince Mourinho to change his mind.

The growing injury list might even earn 22-year-old James Wilson -- back scoring goals for the reserves -- a lifeline more than two years after his last senior appearance.

Whenever Mourinho's injury problems have mounted, the 54-year-old has stuck with the same message: "It is an opportunity for other players."

When Paul Pogba was sidelined with a hamstring injury, the beneficiaries were Ander Herrera and Marouane Fellaini. When Phil Jones and Eric Bailly were ruled out, Victor Lindelof stepped in.

Rashford -- and to a lesser extent Martial -- is the latest to be handed an unexpected opportunity. It is just what he, and plenty of United fans, have been waiting for.