Leinster Rugby head coach Leo Cullen was disappointed with his side’s performance against Ulster Rugby last Saturday, despite progressing to the Heineken Champions Cup semi-finals via a 21-18 victory in Dublin. The defending champions fell behind due to tries from lock Kieran Treadwell and centre Luke Marshall but battled back, with 16 points coming from fly-half Ross Byrne, who started ahead of the injured Johnny Sexton. That win means the Irish province will now host pool stage rivals Toulouse in the last four at the Aviva Stadium on April 21, having won one and lost one match against the French side earlier this season. Cullen – who is the only person to have won the European Cup as a player and coach – admitted his side struggled against their fellow Irish province on Saturday. https://twitter.com/leinsterrugby/status/1112637497203404801 “It was hard viewing at times,” said Cullen. “It was an amazing occasion for the supporters and we are very thankful. “We were a long way off our best and we talked before how difficult it would be. We looked like a team that hadn’t played together for a long time. “Ulster were good in defence, but we are disappointed in the way we went. But we are into the semi-finals now.” Unfortunately, they will be without Ireland back-row forward Dan Leavy, who has been ruled out for the rest of the season and into next term after suffering what the province described as “a complex knee ligament injury” in Saturday’s match, when he lasted 11 minutes as a replacement.