Henry's forward colleague, hooker Andi Kyriacou, is carrying a shoulder/neck injury and is also unavailable.
Stephen Ferris and Rory Best will be rested for Saturday's derby clash in Limerick and are not included in the 32-man panel.
Young forward duo Iain Henderson and Niall Annett have been named in the squad, with the latter in as a cover for Kyriacou.
Henderson played a pivotal role in the Ireland Under-20s' Six Nations campaign earlier this year, while former Ireland U-20 captain Annett has been in fine form for his club side Belfast Harlequins this season.
Munster's only victory in their last four matches in all competitions was a 35-29 success at home to Glasgow Warriors on April 14.
They have lost their last two games at Thomond Park - an unprecedented sequence in the professional era, with one of those defeats coming in the Heineken Cup quarter-final against Ulster.
The two sides also met in the RaboDirect PRO12 in December, with Ulster winning that tie by a 33-17 margin, registering a try-scoring bonus point in the process.
The Ulstermen have slipped to back-to-back league defeats to Connacht and Leinster and will not want to make it a hat-trick against their provincial rivals.
ULSTER Squad (v Munster) - Backs (16): Blane McIlroy, Ruan Pienaar, Ian Porter, Paul Marshall, Ian Humphreys, Paddy Jackson, Paddy Wallace, Ian Whitten, Darren Cave, Nevin Spence, Michael Allen, Stefan Terblanche, Craig Gilroy, Conor Gaston, Andrew Trimble, Adam D'Arcy.
Forwards (16): Callum Black, Tom Court, Declan Fitzpatrick, Adam Macklin, Paddy McAllister, Niall Annett, Nigel Brady, Lewis Stevenson, Johann Muller, Dan Tuohy, Iain Henderson, Willie Faloon, Pedrie Wannenburg, Ali Birch, Mike McComish, Robbie Diack.