“I think I need a full game. Hopefully, that’s what I will get this week,” said O’Brien, who had been out injured since ripping his hamstring against France in February.

“I think with another good run out, I’ll be very close to being match fit. I’ve always said, it always takes two or three games to get up to speed again, especially after a long lay-off. I have to be a bit patient with myself as well and not get frustrated or do silly things on the field.

“I’m not expecting anything, to be honest with you. I haven’t thought about it really. I want to play this weekend to get more game time and see where I am after that.

“That’s the priority. There have been no conversations about that (the game against New Zealand in Chicago).”

Leinster head coach Leo Cullen, admitted O’Brien and out-half Johnny Sexton, who was also replaced at half-time in Montpellier, were seething at being removed from the action.

“I think it’s a natural reaction to any player getting taken off,” O’Brien said.

“You never want to leave the field, obviously. Especially in a game like that where it was tight. You’d hope you could add something to it. I think it’s just a natural reaction. I think every player that gets taken off, unless you’re being taken off for medical reasons (will be unhappy).

“It’s just the way it is. That’s a decision the coaches have to make as well. I was getting through a bit of work. It’s always difficult coming back and getting that bit of match fitness and sharpness. I was glad to be out there and glad to be back playing again.”

O’Brien was told he would be ‘managed’ before the game, but didn’t know that would mean getting the hook at half time.

“I would have stayed trucking for another while if I could. That’s just the way it is,” he said.

“I suppose it was a heavy pitch and a physical game. It was probably a smart thing to do at the time. Leinster and the medical staff have had a plan and they are sticking to that, or there or thereabouts anyway.

“So there was no point in staying out there and trying to play 80 minutes when you’re not adding value or you’re struggling or you could do something silly. I haven’t played in nine months. I’ve played 80 minutes now, two 40s over that duration. It’s a stepping stone and hopefully I get more game time this week.”

Leinster coach Stuart Lancaster shrugged off the O’Brien and Sexton substitutions.

“Take Sean first of all, he hasn’t played for so long, so I see it as a positive,” he said. “The impact Jordi Murphy and Dan Leavy made when Sean came off and also what Joey [Carbery] did when he came on (were positives). Leo obviously felt he didn’t want to take any risks.

“I don’t feel the was anything particularly untoward. Sean’s is a long term injury. Johnny is slightly different. He picked up the small hamstring the previous week but I think it’s sensible for both players.

“Obviously they were disappointed because they are competitive and that’s what makes them the players they are. So when they are told they are coming off they are not happy. In my mind I looked at the positive impact Joey Carbery made and those two back row subs. I think they made a difference from 22-6 to us getting a bonus point.”

I would have stayed trucking for another while if I could. That’s just the way it is