But in the Red Dragons' first Test of the series, the 25-year-old suffered an injury to his chest in the 12th minute before being helped off of the pitch as Wales went on to lose 15-24 to the Springboks.
Scarlets' have been inconsistent in the RaboDirect PRO12 so far - winning three, losing three and drawing once.
And Gatland concedes their talisman could be in for a lengthy spell on the sidelines should an operation on his pectoral muscle be necessary.
"He's pretty disappointed," said Gatland. "Hopefully, it might settle, but if he needs an operation, it could be five months which would mean missing the Six Nations too.
"The physio said it might settle and he could be back in December. We will wait and see what happens."