Doncaster Rovers v Tranmere Rovers: Ryan looks for tackle from the back to be outlawed

Sharp is Doncaster’s most valuable playing asset and his loss, according to Ryan, has delivered a ‘critical blow’ to the Championship club just one game into the new season.

The former Sheffield United striker, 25, suffered damaged ankle ligaments as a result of a hefty challenge from behind by Brighton & Hove Albion defender Lewis Dunk.

Ryan says Sharp, a £3m transfer target for Southampton this summer, would still have been available to Rovers if the ‘tackle from behind’ was still banned by FIFA, the game’s governing body.

Although it was originally outlawed in 1998, the laws were revised in 2005 so that any tackle regarded as ‘endangering the safety of an opponent’ would be treated as a red card offence.

Dunk received only a yellow card for his challenge on Sharp.

Ryan said: “Players like Marco van Basten in the Nineties had to pack in football early because of this type of tackling and I really do think it should have been outlawed a long time ago.

“It was a bad challenge on Billy Sharp and losing him for such a long time is a critical blow to our hopes this season.”

Things went from bad to worse for Rovers against Brighton when striker James Hayter was also stretchered off with a knee injury.

Manager Sean O’Driscoll will now seek cover in the loan market but Ryan says it will be impossible to replace Sharp who scored 32 goals in 64 starts and cost a club record £1.1m fee last summer.

“We will do our best with the resources we have got to bring someone in but, whoever that is, it won’t be Billy Sharp,” said Ryan. “We have a total of nine players missing through injury now and our next league game on Saturday is against West Ham United – a team that will be full of international players.

“I just hope our supporters realise that we need them more than ever now. We are having to contend with a lot of adversity and we need people backing us to the hilt.”

Rovers, who lost 2-1 at Brighton, host Tranmere Rovers tonight in the first round of the Carling Cup.

O’Driscoll said: “It’s difficult for us because we had 16 players for Saturday – and then we lost two . We can have seven players on the bench (in the Carling Cup) but I will probably have to put some of the kids on.”

Teenage midfielder James Baxendale, released by Leeds United this summer, is poised to make his Rovers debut.

Last six games: Doncaster LDDDLL, Tranmere LDWWLW.

Last time: Doncaster 0 Tranmere 0; November 17, 2007; League One.

Referee: G Sutton (Lincolnshire).