Sam Allardyce is unsure whether Manchester City loanee Eliaquim Mangala has played his final game for Everton due to a knee injury.

Defender Mangala agreed to join the Toffees for the remainder of the season late in the transfer window but was forced off in their last game against Crystal Palace on February 10 with a knee problem.

Amid fears the 27-year-old’s issue could prematurely end his campaign, Allardyce was reluctant to put a timescale on how long he is likely to be without Mangala for.

“I think we’re taking a second opinion on what we have to try and achieve with Mangala,” the Everton manager said.

“It’s a very difficult thing to assess just how long it’s going to take, whether it’s going to be longer than first predicted or not.

“At this early stage, while people put a lot of times on how quick you’re going to recover, it can never actually really be the case.

“It cannot be a certainty that it can be eight, 10, 12 weeks at this early stage. You have to judge it week by week.

“Each person has a different healing process, some people take longer than others. (Ramiro) Funes Mori would have been expected to be fit a lot quicker than he is and I think probably Seamus (Coleman) as well, but it wasn’t to be. At this early stage, we shouldn’t put a figure on it.”

Coleman, who is only just back from a double-leg break, is unlikely to feature against Watford on Saturday having picked up a thigh problem, though Leighton Baines could make his first appearance since November following a calf injury.

Ramiro Funes Mori, out for nearly 12 months because of a knee issue, posted on Instagram this week “Ready for Saturday!!!”, yet Allardyce insisted he would make a further appearance for the under-23s before being considered for the senior side.

The Argentinian was among those who travelled to Dubai for a warm-weather training camp during Everton’s two-week break, though Morgan Schneiderlin – booed by some home supporters when he came on against Palace – missed out as he returned to his native France due to a family matter.

Allardyce conceded at the time that he was surprised by that reaction to Schneiderlin, who has now returned to training.

“Like every professional, I think he’ll accept that what he’s got to do is when he gets the opportunity to play, he plays to his very best,” Allardyce added.

“We know he’s good enough to play in the Premier League because of his previous record, when he first arrived at Everton, what he did at Southampton particularly.

“I think it’s one of those that you’ve got to change people’s opinion by performing to your best, let your football doing your talking.”

One player who has impressed Allardyce is Oumar Niasse.

The striker was ostracised under previous boss Ronald Koeman last term but has started the Toffees’ previous three games and is keeping January signing Cenk Tosun on the bench having scored eight times.

“I think Oumar’s position at Everton has never really been as good as it is at the moment,” Allardyce said.

“He’s put himself in a position to shine and score goals. He’s got goals and assists to his name and he’s starting games on a regular basis.

“Oumar’s grasped that position at the moment, making assists, scoring goals, holding it up well, so it’s made it difficult for me to replace him.”