Fraser Forster is facing up to a year on the sidelines after surgery to repair damage to his left patellar tendon, an absence that will have serious implications for Southampton and England.

The goalkeeper, who has enjoyed a fine first full campaign in the Premier League following last summer’s £10m arrival from Celtic, was taken off on a stretcher during Saturday’s 2-0 victory over Burnley at St Mary’s. He fell awkwardly as Sam Vokes closed him down. Ronald Koeman admitted his medical staff’s initial assessment immediately after the game had left him prepared for the worst.

Scans on Monday confirmed the damage to the tendon with the unfortunate 27-year-old – who started every game in the league and had 13 clean sheets – having since had an operation described as successful by the club. The usual recovery time for this kind of injury is between nine and 12 months.

“Fraser is an outstanding goalkeeper and has been a huge part of our success this season,” said the Southampton executive director of football, Les Reed. “While this is a challenging situation, we look forward to him returning to action as soon as he is fully fit. I am sure he will go on to make a significant number of appearances for Southampton and for England, and will get the best support available to help him recover to do so.”

While Koeman will rely on Kelvin Davis for the remainder of the campaign, with Paulo Gazzaniga and Cody Cropper as his understudies, Forster’s prolonged absence may force the club into the transfer market in the summer.

There are issues, too, for England who are already facing up to the reality that Joe Hart’s deputy, Ben Foster, is out for six months after suffering cruciate knee ligament damage while playing for West Bromwich Albion.

Roy Hodgson, who had selected only two goalkeepers in his 24-man party, reacted to Forster’s withdrawal from his squad for Friday’s Euro 2016 qualifier against Lithuania and the friendly in Italy on Tuesday by summoning Jack Butland from the under-21s and Rob Green from QPR. The latter has earned only one of his 12 caps since an error handed USA’s Clint Dempsey an equaliser in England’s opening game at the 2010 World Cup.

Green, who is out of contract at Loftus Road in the summer and is being monitored by Chelsea as a potential replacement for Petr Cech, would appear to be in line to retain his place as Hart’s No2 for the summer’s friendly against the Republic of Ireland and the qualifier in Slovenia on 14 June.

The national side England have further qualifiers against San Marino and Switzerland in September, after which they would hope to have Foster available again.

“I was gutted for Ben and Fraser,” said Hart. “It’s really sad news. It has rocked us all as a goalkeeping group and rocked all the lads in the squad because they are great guys and they are having great season.

“But Rob Green has come in and hopefully he can profit. He did brilliantly in the Championship last year. I remember watching him in the play-off final, when he was man of the match for me. QPR are in a bad position but he has been fantastic this season. He is rock solid. His mentality is great and he is a very good goalkeeper who has been playing at the top level for a long time. There are no surprises.”

The Tottenham defender Danny Rose has also withdrawn from the squad through injury. Rose was called into the squad after Luke Shaw withdrew with a hamstring problem. An FA statement read: “The left-back will play no further part in preparation for the fixtures against Lithuania and Italy and has returned to his club.”