Morgan's inclusion is crucial because of injuries to Willie Walker (shoulder) and Ryan Lamb (ankle) that has restricted Dean Ryan's options at numbers 10 and 15.
However, the head coach is unable to call on Morgan's England team-mate Mike Tindall, who has not recovered from a dead leg picked up against Italy last weekend. That means Anthony Allen, who has not started a senior game since Gloucester's defeat against Agen, will form a centre partnership with Rudi Keil, who scored both tries in Gloucester's 21-12 victory over Saracens in November.
Allen came through a Guinness A League game against Bath on Monday night and is Gloucester's leading Premiership try scorer with four.
"We made it quite clear we would select who we had available to us and that is exactly what we have done," Ryan told www.gloucesterrugby.co.uk
"With the injuries to Lamb and Walker our options are somewhat restricted and we need our best players available for what is a very significant match for us."
The other crucial selections are at half-back, where Rory Lawson is partnered with Ludovic Mercier, who has made only three Premiership appearances this season because of a neck injury.
His last appearance was from the bench against Sale at the end of January. Because of a hamstring injury there is no James Simpson-Daniel which means James Bailey and Mark Foster are the wingers.
The forward pack has a much more settled look to it, although Italian national captain Marco Bortolami, who has made 15 appearances in all competitions this season, takes a turn on the bench.
The front row will consist of Christian Califano at loosehead, hooker Olivier Azam and tighthead Carlos Nieto.
Will James comes in for Bortolami alongside Alex Brown at lock. In the back row, Number eight James Forrester returns following a knee injury, Peter Buxton will skipper the side from the blindside flank and Andy Hazell wears the seven shirt.
"We want to get a good result and we want to win the game," Bortolami said. "The margins between success and failure are very fine but I think this team understands how to be successful and we need to be consistent for 80 minutes.
"Saracens are a very good team with some great players and they are probably one of the form teams in the Premiership, they have been together for the last three weeks and we must be ready."
On the bench, Bortolami is joined by Jake Boer, Nick Wood and Mefin Davies up front, while Peter Richards, Jack Adams and Jon Goodridge - who scored twice in the A League against Bath - are the three-quarter options.
GLOUCESTER (v Saracens), Sunday: Olly Morgan; James Bailey, Rudi Keil, Anthony Allen, Mark Foster, Ludovic Mercier, Rory Lawson; Christian Califano, Olivier Azam, Carlos Nieto, Will James, Alex Brown, Peter Buxton, Andy Hazell, James Forrester. Reps: Mefin Davies, Nick Wood, Marco Bortolami, Jake Boer, Peter Richards, Jack Adams, Jon Goodridge.