Rugby League bosses have hit back at criticism by Sir Alex Ferguson of their decision to hold big matches at Old Trafford.
The Manchester United manager slammed the state of the Old Trafford pitch in the wake of his team's FA Cup exit.
Ferguson claimed it was "madness" to allow two rugby league matches to be played on the surface earlier this season.
The Super League Grand Final was held at Old Trafford for the third time in October, drawing a crowd of 58,132, while 44,329 watched the World Cup final there a month later.
Old Trafford has become a popular venue for rugby league fans since the League began using it as a big-match venue in 1986, and they claim that damage to the pitch is negligible.
"We noted Sir Alex's remarks with interest, and it seems to conflict with evidence from his own club," said Greg McCallum, the Rugby Football League director of rugby.
"We have built up a wonderful relationship with Manchester United over the last few years and we've no reason to believe that anything will change in the future."
Super League, too, have long-term plans to continue to borrow the Manchester United facilities. Although officials declined to comment on Ferguson's outburst, it is understood the League are close to securing a new five-year agreement to use Old Trafford for their Grand Final.
Ferguson blew his top after watching United slip to a 1-0 defeat in yesterday's fourth-round tie against West Ham.
He said: "I can't believe Manchester United has allowed rugby matches to be played on the pitch.
"The biggest club in the world and they have to play rugby every bloody November and the pitch is a mess after it.
"You think they would learn a bloody lesson, and it's an absolute disgrace."