Marshall in for Bok Pienaar as Doak rings the changes
Head coach Neil Doak has made seven changes to his Ulster side that will face Connacht at the Kingspan Stadium this evening (6.45pm kick-off).
There had been hope that Ruan Pienaar, who trained this week, would be fit to play after straining his knee in last week's defeat to the Ospreys but the Springbok scrum-half has not been selected.
Paul Marshall, who performed well in the second-half at the Liberty Stadium, takes over the number nine shirt with Michael Heaney promoted to the bench.
There was some better news on the injury front for the home side however after both Paddy Jackson and Wiehahn Herbst were declared fit to return.
Jackson, who injured his shoulder last month, missed four games but takes the place of Ian Humphreys this evening.
The South African Herbst injured his hamstring earlier this month and Ulster's scrum has struggled in his absence.
While short of match practice, the prop trained well enough this week to convince Doak that he was ready to return.
With the former Shark back in the side, Declan Fitzpatrick takes a place on the bench.
Tommy Bowe and skipper Rory Best are rested, with Roger Wilson captaining the side on what is his 300th professional appearance.
Rob Herring replaces Best at hooker and will pack down in between Herbst and Callum Black, with Andrew Warwick on the bench.
Dan Tuohy and Franco van der Merwe continue as the lock partnership while Robbie Diack and Clive Ross will be the flankers.
With Stuart Olding on the bench, Luke Marshall and Darren Cave will once again be in the centre while the returning Craig Gilroy is joined in the back three by Peter Nelson and Louis Ludik.
Connacht's Pat Lam has also made changes with Irish international centre Robbie Henshaw given the day off.
In the Athlone man's absence, Kiwi Bundee Aki moves from 12 to 13 and is joined in the midfield by Dave McSharry.
World Cup winning All Black Mils Muliaina starts on the bench, with recent Irish squad member Darragh Leader taking his place at fullback, and Danie Poolman and Matt Healy on the wings.
Jack Carty starts at number 10 with John Cooney, on loan from Leinster, starting at scrum-half.
Up front, both props are rotated, with Denis Buckley and Rodney Ah You replaced by Ronan Loughney and Finlay Bealham, and Tom McCartney at hooker.
Quinn Roux, another on loan from Leinster, joins Aly Muldowney in the engine room while the back row contains captain John Muldoon, former Ulster player Willie Faloon and last week's try-scorer George Naopu.
Ahead of the contest, Pat Lam admitted that he has been forced to rotate his side.
He said: "We always knew we would be without Robbie (Henshaw) for this game and would have to manage the other Ireland guys as well. This being a crucial period of games and with a number of injuries, we've made some changes to the starting team.
"It's great for John (Cooney), Finlay (Bealham) and Dave (McSharry) to have the opportunity to start in such a big game. Eoghan's (Masterson) growth in the Academy this season has been exceptional and I'm pleased to give him his first involvement of the season with the senior team after leading and playing well for the Eagles."