Rónan Kelleher is likely to miss Ireland's autumn internationals, while fellow Leinster players Jack Conan and Joe McCarthy will sit out Saturday's URC game against Connacht.
Kelleher was injured in the round-three win over Benetton and the province confirmed he is set for a spell on the sidelines.
"Rónan Kelleher will be unavailable for four to six weeks after undergoing a procedure on an ankle injury," Leinster said.
First-choice Ireland hooker Dan Sheehan is also out with a long-term knee injury and Kelleher’s diagnosis suggests he will sit out the November games against New Zealand and Argentina, while the Fiji and Australia ties may be targets if his recovery goes well.
Fellow hooker Lee Barron also requires further assessment for an ankle injury suffered in Saturday's win over Munster.
Meanwhile, Ireland centre Robbie Henshaw is in line to make his seasonal debut in Galway this weekend after recovering from a lower leg injury.
The former Connacht back hasn't played since Ireland's second Test against South Africa in July.
"He was back on the field today and it was exciting for everyone," backs coach Tyler Bleyendaal told RTÉ Sport.
"He was a bit nervous. He's available, I'm assuming he got through fine, which it looked like he did."
Back row Conan was withdrawn from the derby in the 19th minute with a hamstring injury.
"Jack Conan is unavailable for selection this week after being withdrawn from Saturday’s game while Joe McCarthy (hamstring) is also unavailable after suffering an injury against Benetton," the statement added.
Forward Ryan Baird, who came on as a replacement for RG Snyman after 50 minutes at Croke Park, has entered the graduated return-to-play protocols and will be assessed as the week progresses.
Wing Jordan Larmour was not available for selection at the weekend as a precaution for a hamstring issue, and will be further assessed this week before a final decision is made.
On Saturday's bruising encounter with Munster, Bleyendaal said: "It was hugely physical. Huge credit to Munster, I thought they brought it in pretty much every single breakdown and tackle contest.
"For the most part, I thought we handled it well and matched that physicality, which is great.
"We got off to a fast start but then the game was an absolute dogfight."
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