George North limped off with a calf injury against Harlequins
George North limped out of Northampton's Challenge Cup semi-final on Friday night but is still likely to be fit for Wales' summer tour.
North was replaced by Tom Collins after just 20 minutes of Northampton's 18-10 victory over English rivals Harlequins.
The 22-year-old had picked up a calf strain in the warm-up but felt he was still fit to start the game, only to be replaced after a quarter of the match.
However, Northampton director of rugby Jim Mallinder is hopeful the injury is not serious and that the winger still has plenty to offer club and country this season.
"George North has a calf strain, hopefully it's not too bad," he said.
"He picked it up in the warm-up and thought he was OK to carry on but clearly wasn't 100 per cent.
"Tom Collins hasn't been selected for the England Under-20s so they must have some brilliant wingers. He's been great for us all season.
"Kahn Fotuali'i is a special player. There were two outstanding nines on the field with Danny Care for them, but I thought we marshalled him well." Visit our official RBS 6 Nations Instagram page to follow all the best images from the Championship
Wales flanker Sam Warburton admits he will be proud to lead his country out for a record 34th time this weekend and hopes to cap the day off with a memorable RBS 6 Nations victory against in-form Ireland.