Celtic Cup Quarter-Final: Saturday, April 30Munster v Edinburgh, Thomond Park, 7.30pm (live Setanta Sports Ireland)
The 20-year-old Manning has impressed many observers with his fine displays for the students in their run to last weekend's AIB League Division One play-off and this Saturday's Division Two semi-final.
A former New Zealand schools international, Manning bagged a club record 149 points in 16 league outings this season and with retiring Kiwi Jason Holland failing a fitness test on his knee, the youngster will act as Paul Burke's deputy against the Scots.
Jim Williams is also to miss out on a Thomond swansong as an elbow strain has deemed him unfit for the weekend.
That means Munster will show five changes from the side which accounted for Edinburgh 30-20 two weeks ago in Limerick.
Anthony Horgan replaces Paul Devlin on the wing, Burke comes in for the injured Holland and Gordon McIlwham, Trevor Hogan and Denis Leamy make way for international trio Marcus Horan, Donncha O'Callaghan and David Wallace in the forwards.
Gaffney - another of the departing Munster brigade - has overseen seven wins from seven at the province's Limerick home so far this season and will be wont to cough up that proud record in his final game on Munster soil.
Ireland and Lions fly-half Ronan O'Gara was a definite non-starter as he continues to rehabilitate his knee injury. Samoan signing Brian Lima was also ruled out, with his immediate future at the province uncertain.
The winners of Saturday's night tie will face an away semi-final to Leinster or Glasgow on the weekend of May 6-8.
Frank Hadden's Edinburgh will be all to avenge that defeat as they attempt to match last season's run to the Cup final.
The Scots coughed up an early 13-0 lead against Gaffney's men in their league clash, but received a well-timed boost on Wednesday as their international full-back Chris Paterson was named as the Famous Grouse Scotland Player of the Season.
In Munster transfer news, second row David Pusey is set to return home to Australia after two seasons with the province.
The 26-year-old Pusey - who is to join new Super 14 outfit Western Force - admitted: "While I have had a great experience playing here in Munster over the past two seasons, the chance to get back to Australia to play at the Super 14 level was just too good to refuse."
Head-to-head since 2001: Munster 4, Edinburgh 2Celtic form: Munster: LWWWW; Edinburgh: LWLWLTop League scorers: Munster: Paul Burke 132 points / Christian Cullen 8 tries; Edinburgh: Chris Paterson 103 / David Callam, Derrick Lee, Simon Webster 5 eachCup records: 03/04: Munster: Quarter-finalists (lost 14-18 v Glasgow (away)); Edinburgh: Runners-up (lost 21-27 v Ulster (Murrayfield))
(15) Shaun Payne(14) John Kelly
(16) Eugene McGovern(17) Jerry Flannery(18) Denis Leamy(19) Trevor Hogan(20) Mike Prendergast(21) Paul Devlin(22) Jeremy Manning
Edinburgh Squad: tbc
Referee: Nigel Owens (Wales)