Callum Gibbins to miss Glasgow v Ulster clash due to concussion

The 30-year-old Kiwi flanker suffered a head injury during last Saturday’s 56-27 walloping at Saracens in the Heineken Champions Cup quarter-finals.

“He got a concussion which he didn’t report until after the game,” explained Rennie. “And with such a short turnaround – six days – he didn’t start his [return to play] process until Sunday, so we ruled him out then. He’s a lot better now so we expect him to be right for next week.”

Asked why the problem only came to light afterwards, Rennie said: “He just said after the game that he didn’t feel quite right. There was patches of the game where he couldn’t remember everything, so from there he went through the HIA [head injury assessment] protocol.”

There is better news with the return tonight of wing Tommy Seymour after he  suffered a rib injury in Scotland’s Six Nations game against Wales.

“He was close last week but we made a call fairly early because there were question marks around Hoggy [full-back Stuart Hogg, who did return against Saracens] and we didn’t want to have too much uncertainty. And we wanted to give Tommy a full week training which he has now had, and with his experience and ability under the high ball, that will be massive for us. It’s great to have him back.” Rennie is expecting a fierce battle in tonight’s cross-Conference tussle. His Glasgow side lead Munster by three points in their group while the visitors, led by former Warriors and Scotland forwards coach Dan McFarland, are battling for the play-off spots in Edinburgh’s section.

“I think everyone is desperate this time of year,” said Rennie. “A win is really important for them to cement a place in the play-offs.

“They are out of Europe as well [after losing to Leinster last week], so they’ve only got one focus left, the same as us.

“Obviously, we know a lot about Dan and they will have a really well drilled pack, and they are also very good at choking you with a lot of possession down your end of the field. We know what’s coming: we are going to have to be really resolute defensively, and accurate with accurate with the ball to stretch a really good defence.”