Manchester United must spend between £30-40 million if they're to adequately replace midfielder Paul Scholes, according to former player Mickey Thomas.

The 37-year-old is unbeaten in a United shirt since reversing his decision to retire at the end of last season, in January, producing a series of assured displays during the Old Trafford club's surge to the top of the Premier League table.

However, with Scholes yet to commit to another full season with United, the club may be forced to invest in a replacement for a player who Thomas believes has been among the club's best this season.

"Without doubt he's incredible and I'm made up that he's back," Thomas told talkSPORT.

"He's the player of the season if Man United win the title.

Paul Scholes
Manchester United surge to the top of the Premier League coincided with Paul Scholes' return. Reuters

"It was crucial that he came back. We haven't got a player like him at the club, someone who can unlock defences with his long range and short range passing.

"To get a player like him it would cost £30-40million and maybe more because there are not many like Paul Scholes about.

"[His return] was a big, big bonus for Sir Alex Ferguson. He's a clever footballer. I don't think he should have [retired] and I think he'll be here next season."

Despite a raft of names being linked with possibly replacing Scholes, who has given United over 18 year's worth of service, the club have found the transfer market lacking value.

Their well-documented pursuit of Inter Milan's Wesley Sneijder was fraught with problems, not least due to the Dutchman's astronomical wage demands of £250,000-a-week and valuation in excess of £30 million.

United encountered similar issues when chasing Borussia Dortmund's attacking midfielder Mario Gotze with the German rated at £33 million, while his new contract extension has also helped warn off interest.

Any interest in Thiago Alcantara last summer was quickly extinguished by Barcelona including an €85 million release clause in his new two-year contract, following a spate of impressive displays in Spain's victorious Under-21 European Championship side.

Fellow club legend Ryan Giggs, another who is in the twilight of his United career, has previously stated the club will never be able to replace Scholes.