O'Brien may not make Toulon return leg
Leinster will have to survive without Sean O'Brien tomorrow and the Ireland flanker is unlikely to make it back for the Toulon return leg.
"Sean saw a specialist that he's seen a few times, he went back at the start of the week. He's still under fatigue, suffering a balance problem," said coach Leo Cullen.
"We're just not taking any risks. It's a slightly unusual issue. If he did get a bang he'd be more susceptible to dizziness. But he's making progress."
Second row Hayden Triggs will not be back for six weeks after undergoing an ankle operation.
Nonetheless, Cullen will play something close to his strongest hand against Toulon.
Certainly, Rhys Ruddock is one man who won't be overpowered in a match of muscle.
"Since the defeats in the earlier rounds there was a hurt and a feeling that we wanted to bounce back and get that winning feeling back.
"I think Ulster was the start of that," Ruddock stated.
The postponement of the Glasgow game last week could be a blessing in disguise in that there have been no additions to the injury list.
Leinster have also had more time to analyse and to prepare for what's coming.
"We are a competitive side. Every time we take the field, we want to get that feeling of winning," he said.
"Going over to play Toulon away in the Champions Cup, you don't need much more motivation than that.
"There is added excitement around the place anyway.
"Everyone's prepared really well and had that edge about them this week.
"This is the reason we play the game, for days like these."