England prop Matt Stevens has been ruled out of the tour of South Africa after suffering a shoulder injury, the Rugby Football Union has confirmed.
South African-born Stevens, 29, who only returned to rugby last year after serving a two-year suspension for testing positive for cocaine, damaged a rotator cuff during England's win over the Barbarians on Sunday.
It is a cruel twist for the Saracens prop, who had battled his way back into the England squad despite his lengthy enforced lay-off from rugby. He will be replaced by Gloucester's Rupert Harden.
"Firstly, it's really tough on Matt but he has been assessed by the medics and he wouldn't be able to train or play for some time," England head coach Stuart Lancaster said.
"We wish him all the best but it's a great opportunity for Rupert, who has been the first-choice tight head for Gloucester this season and was also involved in the Saxons during the Six Nations."
England, who depart for South Africa on Wednesday, are already facing concerns over the fitness of fly-half Toby Flood and the availability of Leicester Tigers centre Manu Tuilagi.
Tuilagi could miss the entire tour to South Africa after being cited for a "tip" tackle on Danny Care during last weekend's Premiership play-off final against Harlequins at Twickenham.