"The news comes as a blow to our ambitions to retain the RBS Six Nations title," said Ruddock. "Chris Horsman came through the Invesco Perpetual Series with flying colours. His positive attitude to the scrummage rubbed off on other players and his work outside the scrum was also impressive.
"It's a big blow to Wales but I really feel for Chris who had only just broken into the team. It must be very disappointing for him on a personal basis.
"We wish him a complete recovery, bearing in mind that we also have him in our mid to long term plans with the Rugby World Cup in mind.
"The news should give other players the chance to go all out to prove themselves ahead of the RBS Six Nations campaign. As with all injuries, it is a chance for players to grab the opportunity with both hands and try to hang onto the red jersey if they get it."
And Horsman has been a major factor in his club's excellent season. Worcester's Director of Rugby John Brain said: "Chris has been playing through the pain from his ankle for some time now and the point has been reached where surgery is the only real option.
"It is a blow for us, but not an unexpected one and we have enough quality props at the Club to deal with the situation. Until the surgery has been completed we can't be sure exactly how long he will be out of the game but we'll do everything we can at the Club to ensure that his recovery will be complete."