With the conclusion of the Six Nations, the European Champions Cup is the only way for potential Lions players to put their hand up and be counted between now and when the squad is announced on April 19.
Of all the positions, those in the backrow in particular look to be the ones with the greatest amount of competition for a place, and with three flankers as well as Jamie Heaslip in the debate, it is highly unlikely that all will go. Actually, there's no chance of that happening.
Speaking in a live Periscope ahead of BT Sport's Rugby Tonight, Brian O'Driscoll expressed his belief that Sean O'Brien, Peter O'Mahony, and CJ Stander were in a three-way battle for one spot when asked about the Cork man's chances of making the squad.
I think Peter O'Mahony has had a huge game against England but he essentially hasn't been playing for the national team.
Would he do a brilliant job in the midweek team? That's what a lot of people are talking about. You've got to pick guys in the test reckoning. When you look at the strength of the back row, I'm not sure he features in that with the best of them.
It will be interesting to see what happens. I think one player gets picked between Sean O'Brien, Stander and Peter O'Mahony.
I don't feel it's likely to be Pete and it would be some shock if they left Stander out. Don't be shocked of you see Sean O'Brien in the squad, even though he hasn't been playing the best rugby of his career. He played at 7 in the third test in Australia in 2013 and played really well.
Warren Gatland likes him and Andy Farrell likes him, so don't be shocked if you see Sean O'Brien in the squad, even though he hasn't been playing the best rugby of his career.
— Rugby Tonight (@RugbyTonight) March 29, 2017
So if you can only pick one, who are you taking?
On current form CJ Stander would be the pick for many, but O'Mahony was unlucky regarding the chances he was given in the Six Nations and made the most of it when picked against England.
O'Brien had an underwhelming tournament, but there's no doubting his ability and as O'Driscoll said, the coaching staff are fans of his.
It's a tricky situation for sure, and it will be interesting to see what happens as all three players are well capable of touring well, but with so much competition from other countries there is no way all three will go.