Billy Vunipola says kicking an Australian guidelines soccer was behind his most up-to-date harm.
The Saracens quantity eight, who heads to South Africa with England on Saturday, needed to come off at half-time within the Premiership semi-final win over Wasps with a hamstring drawback.
However Vunipola, 25, was fit enough to play 60 minutes in Sarries’ Premiership final win over Exeter on Saturday.
He mentioned: “It was my fault, I used to be doing AFL kicking and the hammy went tight.”
Vunipola added: “I educated absolutely the week earlier than towards Wasps [in the play-offs] and I felt actually good.
“I did not inform the coaches that, however after I got here off at half-time towards Wasps I advised them. I used to be like, ‘sorry guys, I used to be doing AFL kicking’. I sewed myself up there.
“I needed to handle myself a bit higher the week after. Now I really feel sturdy once more.”
Vunipola, who has had an injury-interrupted season, has not performed Check rugby since March final yr, however is a part of a 34-strong England squad aiming to win a sequence in South Africa for the primary time.