A former Sheffield United boss has said football clubs could make millions a season by selling naming rights to historic stadiums.
Trevor Birch, a one time chief executive at Bramall Lane, has said ditching the name in favour of a sponsor's name was "emotive" but said it was an area under-utilised as a revenue stream.
Birch now works for corporate finance advisors Duff & Phelps, who have released a study into naming rights values in the Premier League - and the survey predicted Manchester United could make £26 million a season by selling off the naming rights to Old Trafford.
The firm believes the value of the market has risen by 80 percent from £74.6m in 2013 to £135.6m last year, with the league's 'big six' accounting for more than three quarters of that sum.
United, however, have repeatedly said they have no intention of selling the naming rights to their 75,000-capacity home, a stance that has not changed.
The study ranks Manchester City's Etihad Stadium at £19m, Chelsea's Stamford Bridge as the third most valuable naming rights deal at nearly £18million a year, with Spurs' new White Hart Lane worth a potential £15.5million to a sponsor - marginally more than Emirates' deal with Arsenal.
Liverpool's Anfield is in sixth place at £11.1m, but this is probably a reflection of the fact the naming rights to famous old grounds are not particularly attractive to sponsors as very few people ever use the new names - a point that could also be made about Old Trafford.
Mr Birch said the valuations were 'not an exact science' and were 'potential, theoretic valuations that might not be achievable on the market'.
He added: 'It's an emotive topic, particularly in this country, but it's an area that is definitely under-utilised as a revenue stream."