O'Mahony came off the bench last weekend as Munster held off their arch rivals Leinster to claim a stunning victory at the Aviva Stadium.
This weekend sees the flanker, who is returning from shoulder surgery, gain his first start as they host the Scarlets at Thomond Park.
And the Ireland international admits he is still finding his feet after nearly seven months out with injury.
"I'm delighted to be back," he said. "It is one thing you miss is just warming up with the group rather than on your own and doing your own sessions while the lads are getting stuck into training. It's been great to get back involved and to get on the pitch on Saturday - it was a great feeling.
"It was a great first-half performance. It could have been better in the second half - we probably let them off the hook a little bit, which we were disappointed about - but it is a positive. The most important thing for us is to back it up next weekend.
"With two reconstructed shoulders I will be fairly stiff and sore for the next few months. Structurally they are sound, I have been told by the doc, so it's not a concern when they are sore but what can you do?
"I probably need eight to ten games. The lads have had two warm-up games and five rounds in the league - they have seven games on me at this stage. I will probably be looking at eight full games to be back."
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