In addition he may not know till later in the day whether or not Damien Varley is available to him for selection. Varley travels to Edinburgh this morning for a Disciplinary Hearing after being sent off in the game against Ospreys.
Ticket sales for the game on Saturday have again passed the 40,000 mark for this eagerly anticipated clash. Last season over 48,000 turned up to see Leinster win 24-19 thanks to seven Johnny Sexton penalties in a game that started disastrously for Munster who lost Keith Earls to injury after just two minutes of play.
The areas that may well cause Penney to ponder most are midfield where Casey Laulala, James Downey and Keith Earls vie for the two centre berths and the back-row where any one of six - Dave O'Callaghan, Tommy O'Donnell, Sean Dougal, Niall Ronan, Paddy Butler and Peter O'Mahony - are all more than worthy candidates.
If this is a game too soon for Murphy and O'Dea then the wing commanders will be Doug Howlett and Simon Zebo who twelve months ago watched this game on TV and though now one of the young 'veterans' with 35 Munster caps, has yet to play at the Aviva. "Yeh, really looking forward to it. To play for Munster there in front of 40,000. It's going to be awesome." he said.
His counterpart Doug Howlett described the performance against Ospreys last weekend as "probably the little bit of a wake-up we needed." and continued, "A real challenging game like this (Leinster) is what we need to really find out where we are and these interpros give you exactly that. We had a little taste of that earlier against Ulster. We were short by one point. A torrid affair at that and we're expecting the same against this week."