Johnny Sexton has returned to training with Leinster and may feature against Ospreys on Friday.
The Ireland out-half underwent shoulder surgery after suffering an injury during the Pro12 final loss to Connacht at the end of last season.
Sexton subsequently missed out on the tour of South Africa, where Ireland beat the Springboks in the first Test before losing the next two games.
Today, the province, who beat Edinburgh in the Pro12 at the weekend, issued an injury update on the 31-year-old.
“Johnny Sexton returns to training this week and will be assessed later in the week for Ospreys,” they said.
Fergus McFadden and Rhys Ruddock are also in the running for selection but will be checked closer to the RDS tie (kick-off 7.35pm).
As reported last week, Rob Kearney will miss the “next few rounds” with a grade 2 PCL knee injury.
Leinster’s first Champions Cup outing is a home game against Castres on 15 October.