Definitely ruled out of contention for the tour is Glasgow Warriors and Scotland outside half Duncan Weir, who suffered a suspected broken leg in his side's crushing win over the Ospreys at Scotstoun. Weir was carried off on a stretcher and is likely to be out until next season.
"Duncan will miss the rest of the season and probably be out for the start of next season, which is a real shame for him. For him to miss out on the last couple of games will be disappointing, but there will be other players who can take their opportunity and play for Duncan," said Glasgow head coach Gregor Townsend.
Ospreys and Wales hooker Richard Hibbard also limped out of his side's 35-17 defeat and looks set to be laid up for the next month after damaging knee ligaments. The Ospreys have one more regular game to play in the RaboDirect PRO12 and could creep into the play-offs.
The third injury came at Sixways where Harlequins and England skipper Chris Robshaw limped out of his side's win at Worcester Warriors after 55 minutes with an ankle injury. He is definitely out of the reigning champions' game with Northampton on Saturday - the final game of the regular season - but of more concern is whether he will be fit for the knock-out stages in three weeks' time.
"He came down on his ankle when he came down from a line-out," Conor O'Shea, Harlequins director of rugby, said. "He hobbled into the shower.
"We'll just let it bleed and see where it is in 24 hours. It's pretty swollen and he came out of the changing rooms in a moon boot. I wouldn't say it was precautionary as he twisted his ankle but he'll be fine. Maybe not for next week, but we've got three weeks until the semi-final so he should be fine for that."
Better news for Gatland was the re-emergence of two of Wales' 2012 Grand Slam players, Scarlets outside half Rhys Priestland and Cardiff Blues lock Bradley Davies. Both players came off the bench in the home side's 24-6 win at Parc y Scarlets.
Priestland missed the 2013 RBS 6 Nations after rupturing his Achilles, while Davies was ruled out with a dislocated ankle.