Manchester United would be dealt a massive blow if they were to lose the services of "irreplaceable" striker Wayne Rooney, according to former Chelsea midfielder Micky Hazard.
The ex-Blues star was speaking to talkSPORT on the Alan Brazil Sports Breakfast Show, where he reserved praise for the England international after a series of impressive performances this season.
The Red Devils have endured a poor start to the 2013/14 campaign collectively, and currently sit ninth in the Premier League table, but the excellent individual form of Rooney will provide reason for David Moyes to be optimistic about the Old Trafford outfit's chances of closing the gap on leaders Arsenal.
Rooney has been the leading light for Manchester United this year, and with just 18 months remaining on the 28-year-old's current contract, Moyes must surely prioritise offering him a new long-term deal.
Chelsea were heavily linked with a move for Rooney during the summer, and there were fresh reports on Wednesday night that Jose Mourinho is planning a renewed bid to lure him to Stamford Bridge in January.
It's nothing more than speculation at the moment, but Hazard is adamant how detrimental Rooney's departure would be for Manchester United.
"Manchester United are in a transitional period and they're going to struggle this season," he said. "They may come again next season but, in that period, if they were to lose Rooney who, for me, is they're best player [it would be a blow].
"At White Hart Lane, Rooney was outstanding. He was the difference between Tottenham winning and Man United getting a draw.
"If they lose him, and particularly to one of their rivals, they'll find it very hard to replace him. It would be a big loss."