England international Billy Vunipola chances of featuring for the upcoming tour of South Africa has taken a further setback following a hamstring injury.
Vunipola experienced stiffness in his hamstring while training with his club Saracens on Wednesday. The 25-year-old's career has been marred by injuries and he recently recovered from a broken arm and returned to action last weekend for the clash against London Irish.
Saracens boss Mark McCall insisted that Vunipola will be rested this weekend for the final round clash against Gloucester and hopes he will return in time for the play-offs.
"[The hamstring] hasn't been pulled or anything as far as I know," McCall told BBC 5 live.
"There are two and a half weeks until the semi-final, so all things considered it's probably best he doesn't play this weekend.
"If anyone has a hamstring tightness on Wednesday, it wouldn't be the most sensible thing to play him [on Saturday].
"Maybe having not played rugby for a long time, these kind of things can happen quite easily."
With 72 points from 21 games, Saracens have already sealed a home semi-final spot in the ongoing season of the Aviva Premiership.