St George Illawarra are sweating on the fitness of Gareth Widdop, after the star five-eighth reportedly sustained a potentially serious quad injury.

Widdop suffered a corked thigh last Sunday during the Dragons’ shock 28-26 defeat to Gold Coast and is in serious doubt for the side’s final-round clash with Wests Tigers this Saturday.

High performance manager Mark Andrews said the severity of the injury only really surfaced this week, and there were no guarantees the English international would be able to play.

“During the time we flew back (from Queensland) and he came into training it has bled, so at the moment we’ve sent him for scans and to have a look at it,” Andrews said on Thursday.

“He’s under observation at the moment, so the reality is in terms of whether he plays this weekend or not, we’re not quite sure yet.

“But we’ll know soon and hopefully that settles and it’s nothing too major.”

Unless they get thrashed by the Tigers and Manly do a similar job on Cronulla the Dragons will remain in eighth because of a superior for and against.

But the absence of star playmaker and first-choice goal-kicker Widdop would be a serious blow to any progression in the finals.

Joel Thompson has already been ruled out this week after the back-rower re-strained his hamstring, while Dylan Farrell is being rested as he continues recovery from a stress fracture in his back.