Gary Neville has warned Man Utd fans not to expect an immediate impact from Bruno Fernandes as the club seals the midfielder's signature.
United have agreed a deal with Sporting Lisbon to buy Fernandes for a fee in the region of £67.8million.
Ole Gunnar Solskjaer was desperate for midfielders with both Paul Pogba and Scott McTominay sidelined through injury, and Neville feels the capture of Fernandes is "essential".
Speaking to Sky Sports, Neville said: "I've not got huge expectations of Bruno Fernandes in terms of this next few months.
"I think it'll take him a little time in England to settle in. He'll need some time.
"But they've got a good, quality player into the building. Utlimately we shouldn't be sat here thinking he's going to be amazing straight away.
"Obviously it's very difficult to hit the ground running in the January transfer [window]."
Should Fernandes complete his move, he could be in line to make his debut against Wolves at Old Trafford on Saturday.
He has scored 13 goals in 22 appearances for Sporting so far this season.
The 26-year-old pushed for a move away in the summer, but a deadline day switch to Tottenham collapsed after Spurs refused to meet Sporting's asking price.
A similar issue looked likely to scupper United's approach for Fernandes this month, as the club's haggled over a fee.
But United posted an update to their official website on Wednesday confirming talks had progressed significantly.
" Manchester United is delighted to announce it has reached agreement with Sporting Clube de Portugal for the transfer of Bruno Fernandes," the post read.
"The deal is subject to a medical and the agreement of personal terms.
"A further announcement will be made in due course."
