The frontman has yet to figure since joining United from Leicester City on the final day of the January transfer window, and – if Benítez’s prognosis is accurate – he will now sit out this weekend’s clash at AFC Bournemouth as well as next Saturday’s trip to Liverpool.

“Slimani had a setback the other day so he will not be available,” the Magpies’ boss said. “It will be at least another couple of weeks that we have to keep working with him, because he had an injury when he came and then he had a setback and we just have to deal with that.

“We were working really hard, trying to bring in a player that could give us something different, with experience in the Premier League. We knew he was coming with a small injury but still he has had little problems and now, the last day, he needed to stop, and check again, and we will need a couple of weeks.

“Everybody was expecting him to make the difference. The only positive is that after the game against Manchester United we feel we have enough quality in the squad to cope with the games. Always, a new player – and added competition up front – could help. Hopefully it will help in the next games.”

Benítez added: “He was training really, really hard. I was watching him training the other day, talking with him and was quite positive. He was feeling really well, training really well, and then he felt the problem a little bit, so we have to be sure that next time he is OK.”

Victory at Bournemouth tomorrow will see United leapfrog the Cherries in the Premier League table, and with a little bit of help from elsewhere, the Magpies could even return to the top half for the first time since October.

On the other hand, defeat at Dean Court could leave Benítez’s side precariously close to the bottom three – such is the congestion in the battle to avoid the drop.

“It is important to understand that if you win, it’s fine, but still you have to keep fighting. And if you lose, it is not the end of the world because you have a lot of teams around and still a lot of games,” the Spaniard said.

“We have had a bad run, Bournemouth have had a bad run, and Huddersfield have had a bad run, so as soon as you win a couple of games then you go three or four positions up in the table. It’s really, really important for us to do well and if we can get another three points it would be massive for the confidence of the team.”