Justin Burnell says London Welsh must improve their discipline for the Greene King IPA Championship play-offs.
The Exiles’ head coach was left frustrated after his side received a second successive red card during their 64-12 victory over Nottingham.
Replacement hooker Alec Hepburn was sent off for a tip tackle, following flanker Richard Thorpe’s dismissal for punching in their previous match against Bristol.
The message from Burnell is clear – the Exiles can ill afford to go down to 14 men when they face Leeds in the semi-finals on May 11 and 18.
He said: “It was a nice way to finish, ten tries and a good performance, but discipline once again let us down.
“That’s a major concern for me. We’ve got to learn from that – we’ve got to keep our 15 players on the field.
“When we’ve got 15 players on the field there is no room for anybody to break us.
“That was the disappointing aspect for us and that’s our own fault.
“When you do go down to less numbers, the defence does get opened up.”
Burnell added: “In the league system, you’ve got the opportunity to rectify problems the following week. You don’t get that opportunity in the play-offs.
“You’ve got to win those games, because it might be the last game you play.
“And it’s about maintaining a clean sheet, as we did when we had 15 players on the pitch.”