However, he also insisted the fullback was influenced by an injury he suffered in the lead-up to fouling Harry Wilson.
He said, "I think what the team showed today, the character they showed, that's also what Robbo showed. Sometimes if you get a kick like this, two studs on a knee, that can hurt for a few minutes. Then, if you just keep on running, it gets better and better and that's what we were hoping for.
"Not least because I only had one defender on the bench, who was not a left full-back as well. So, we were hoping he was managing to come through it and I think he did quite well, but the moment I noticed he wasn't completely himself was the one time they put the ball in behind and he started running. He was just able to head it back to Ali (Alisson Becker), but I thought, 'OK, let's see how this continues' and I think it was quite quickly afterwards where he conceded the red card.
"Nothing to blame on him, (it was) character that he wanted to continue because he got quite a hard knock on his knee with two studs. Unfortunately it led to a red card that was a deserved red card."