Leo Cullen said Leinster are "playing by very different rules" to European powerhouses Toulon after their 20-16 Champions Cup defeat to the French giants at the Aviva Stadium on Saturday.

The Champions Cup holders produced a devastating second-half performance to consign the Irish province to their fourth pool defeat, and extinguish the slim hopes Cullen's men had of making the quarter-finals.

Cullen praised his team's efforts but admitted they were ultimately "outgunned", and said Leinster must now step back and evaluate how they can move forward and challenge the big hitters in the future.

"Toulon have I think 16 foreigners they’re allowed bring in to their squad whereas we’re playing by very, very different rules," the head coach told RTÉ Sport. 

"We’re about trying to grow our own talent and it’s a challenge. Five or six years ago the likes of Toulon, they didn’t exist really as a European force. We just need to have a really good think about the way we do things.

"It’s tough playing against those big bodies, that’s the reality of it"

"This campaign has thrown us a lot of questions for sure. We just got outgunned the last couple of weeks."

The hosts led 16-5 at the break, Jonathan Sexton converting a 17th-minute penalty try and firing over three penalties, but they didn't add to their tally in the second half as the French giants overwhelmed them..

“I couldn't fault the lads with their first-half efforts," said Cullen. "I thought they showed good intent at the start of the second half. Unfortunately we just played our way into a bit of trouble.

"We defended really well for the early part of the second half but the power did just wear us down and eventually it was just too much for us. It’s tough playing against those big bodies, that’s the reality of it.

"I understand the toll it takes when we defend for long periods. We’d a fantatsic crowd here. It was a great occasion. For us Euope is over and it’s about focusing now on the Pro12 next week, a huge game against Munster. It doesn’t get any easier.

"It’s important we reassess and get ourselves ready for next week.”