Paul O'Connell and the majority of the province's international contingent are reportedly 'on schedule' to make their seasonal bows in the interprovincial derby against Ulster in two weeks' time.
Before that, Penney's men have to venture to Edinburgh before entertaining Benetton Treviso at Thomond Park next week.
Tommy O'Donnell will sit out the league opener with bruised ribs, an injury picked up in last week's friendly defeat to London Irish, but the Tipperary native is hopeful of making a quick return.
"I just got a bang in the ribs and there was bruising that rules me out for this week. I went to Cork University Hospital where they checked me out. Everything was clear, just bruising thankfully nothing serious," he told the Munster website.
"So I hope to be back in full training and in with a chance of a place for the Treviso game. Obviously if you train for ten weeks and then miss out with a little bit of an injury it is disappointing in that respect, but I wouldn't begrudge anyone coming in behind me. Once we get a win and I'm back next week I don't mind too much."
O'Donnell's back row colleague Niall Ronan, the man in possession of the number 7 jersey up to the time of his cruciate knee ligament injury last season, is back in full training.
He took part in full contact during Tuesday's training session in Limerick, for the first time this season, and his return will make for a very interesting battle for the openside berth with newcomer Sean Dougall another player to impress during pre-season.
As things stand, O'Connell and the likes of Ronan O'Gara, Keith Earls, Simon Zebo and Conor Murray are due to return in Munster colours against Ulster on Friday, September 14, with Donnacha Ryan and Peter O'Mahony expected to return a week later at home to the Newport Gwent Dragons.
Munster team manager Niall O'Donovan said: "It is in all our best interests to look after the players and make sure they are able to play the vital games we want them to play. You'd love to be able to play Paul O'Connell week in, week out but you can't.
"So, you have to get a guy who is gone into his early 30s now and mind him, and it is the same with the younger guys coming through, like Peter O'Mahony, and make sure they are getting the proper pre-season and make sure they are ready to go into battle when the time comes.
"We work closely with the Irish management on when we can slot guys in and when we take them out. So they'll play a certain amount of games in the first lot of the season, but they'll have their time off as well. And they have to have their time off, otherwise they are a spent force."
Versatile forward David O'Callaghan (calf) will be back in two to three weeks' time to stake his claim for matchday duty, with second row Ian Nagle still about a month off a return.
Two of Munster's Ireland-capped forwards, Donncha O'Callaghan and Mike Sherry, are likely to see RaboDirect PRO12 action sooner rather than later, while fellow international Felix Jones is well on course for his predicted November return.