Johnny Sexton is expected to make his long-awaited return to action on Friday night against Glasgow Warriors if he comes through today’s training session at UCD with no adverse effects.

The Leinster and Ireland captain has been sidelined due to concerns about head injuries since April 10, but has been reintroduced to contact training this week with a view to a return to action.

The 99-times-capped Ireland skipper will get a chance to show Lions coach Warren Gatland what he’s missing if he is cleared to play and Lions assistant Robin McBryde said the out-half, who has started five of the last six Lions Tests and came off the bench in the other, could yet play a role.

“That standby list is going to play a vital role,” he said.

“And especially for people who have that amount of experience, who are winners and have experienced playing at the highest level in Europe and internationally, competing at the top of the Six Nations, winning a Grand Slam, etc.

“You look at the history of the successful teams in both of those competitions, Six Nations internationally and then domestically in Europe, and both of those players (Sexton and James Ryan) are involved with one of the best teams in Europe.

“It’s going to put them in a good place. They’ve got to keep the bit between their teeth and keep going, striving to improve, and making sure that when that opportunity comes, that they are ready for it.”

Sexton’s Ireland team-mate Will Connors has been ruled out for the rest of the season after undergoing knee surgery, while Jamison Gibson-Park is nearing a return.