Ole Gunnar Solskjaer is not sure where Ander Herrera's future lies and suggested the uncertainty may have impacted the Manchester United midfielder's fitness.

It is understood that the 29-year-old wanted to stay at Old Trafford and sign a contract extension, only for a lack of communication to see the Spaniard plan on leaving at the end of his deal.

Herrera is believed to have committed to Paris St Germain over another option, although Solskjaer's appointment brought up a renewed push from United to agree terms to keep him beyond the summer.

"He's been working really hard to get fit from his injury that he sustained against Liverpool," the Red Devils boss said.

"Then he came back, and he got a different one here in training because he's been really putting a lot of work in.

"And, unfortunately, that's come at a time where, as you say, there are contract talks but that's ongoing, so I can't really comment too much on how far they have come down the line and what he's deciding.

"Well, you have to ask him (if there is any chance of him staying). I don't know how they've been, the last few talks, but we've let him focus on his fitness as well.

"He loves to play and he's not very happy when he can't help his team-mates and he's always giving his all - it doesn't matter if he's got five years left of his contract or five weeks."

Alexis Sanchez has returned to training, but isn't fully fit

Herrera is ruled out of Saturday's Premier League clash against West Ham with a muscle complaint sustained shortly after recovering from a hamstring injury.

Solskjaer, rather surprisingly, suggested that those injury issues could have been contributed to by the uncertainly over his future.

"Maybe the future might have been worrying him and maybe that's part of the reason that he's injured," the United boss said. "Who knows?

"He doesn't know because he got a different injury in training. Hopefully he can be available for around about Chelsea (28 April), City (24 April) but I'm not sure because he got another muscle injury."

Herrera is one of a number of absentees for this weekend's match against the Hammers, with Nemanja Matic likely to be laid low again by illness.

Luke Shaw and Ashley Young are suspended but Matteo Darmian is available and Marcos Rojo could well come in at left-back for his first start under Solskjaer.

Eric Bailly and Antonio Valencia also look set to miss out once again, so too forward Alexis Sanchez as he returns from an ankle injury.

"He is training with us," Solskjaer said of the Chile forward.

"I'm not sure if he's going to be available. He's injury free but I am not sure if he's 100 per cent, maybe more likely for the Barcelona game (next Tuesday), so let's see."