Kilcoyne was included in the extended squad at the start of the Six Nations campaign and has since impressed for Munster in two bonus-points wins over Cardiff Blues and Zebre, with the prop scoring his third try of the season against Cardiff.
Ryan played 68 minutes as he made his return from injury on Saturday night in the bonus-point win over Zebre and is drafted straight into the squad.
The win over Zebre was a landmark occasion for Donncha O'Callaghan as he surpassed Ronan O'Gara as Munster's most-capped player and, having recently signed a two-year contract extension, the Cork man revealed there is still plenty left in the tank.
O'Callaghan said: "I suppose physically I'm getting good scores and that matters to me and I'm just a little bit driven. I want to achieve and straight away you think of [Munster cap] 242 and I think of [Ireland cap] number 95. That's what drives me and that's the competitive nature of it.
"You see the bigger picture as well and you see the squad we have and it's about making sure of the little things that you can influence by the way you conduct yourself and the legacy that other fellas have left, the standards. I'm not saying you enforce them but you make sure guys are aware of them," he added.
On the injury front, Dave O'Callaghan will see a specialist today after injuring his right knee in the first half on Saturday night. Duncan Casey also had to be replaced with a dead leg.
Head Coach Rob Penney has said that he is planning on getting reinforcements in the hooker position after a number of injuries with Casey joining Mike Sherry (knee), Damien Varley (delayed concussion - expected to return to training this week) and Niall Scannell (hyper-extended elbow) on the treatment table.
He said: "We're investigating [who's next in line] so you'll know pretty shortly where we're going to with that. We're making progress on that."
The squad will have a down day today to recover from any bumps and bruises picked up at Musgrave Park with the players returning to their training centres tomorrow to begin preparations for the trip to Ospreys on Sunday.