Leinster are likely to miss the services of Ireland international Johnny Sexton for the crucial Heineken Champions Cup clash against Ulster in Saturday's game at Aviva Stadium following an injury.
Sexton, who suffered a knee injury in January also had thigh problem during the recently concluded Six Nations tournament and will sit out of the vital encounter. James Lowe will also miss out due to 'overseas' players limit with Scott Fardy in second-row and Jamison Gibson-Park on the bench.
Leo Cullen's side will also miss the services of Josh van der Flier, Devin Toner and Robbie Henshaw while Ulster will miss Will Addison and Craig Gilroy due to injuries.
Meanwhile, Billy Burns, who arrived for Ulster in 2018 from Gloucester lavished praise on the World Rugby Player of the Year.
"I don't think it's for me to say how he played in the Six Nations," said Burns.
"He's shown that he is a world-class player before.
"He's a top quality player, he's led both Ireland and Leinster to massive honours over the years. I wouldn't even say he is particularly out of form to be honest. And if he is out of form, I'm sure it won't last long."
This will also be the 24-year-old's first game at Aviva Stadium and has never lined up against Sexton before - someone who he had idolised.
"I'm hugely excited," Burns added.
"I've been watching a lot of his game this week and over the past few years.
"He's been probably the best fly-half and player in my position and I've tried to learn as much as I can from just watching his games."