Rovers earned a point in a scrappy match played out at a muddy Roots Hall.
Mathieu Baudry, Joe Wright, Matty Blair, Jordan Houghton and Luke McCullough all came into the starting line-up for Rovers, with boss Darren Ferguson able to welcome back a number of players from injury.
Blair was originally named on the bench, but was elevated into the starting line-up after Craig Alcock was forced out with a groin injury.
Andy Williams and Issam Ben Khemis also made their comebacks to claim a place on the bench.
It was a scrappy affair from the off, with Rovers’ early opportunities coming through free-kicks and corners.
That almost led to the opening goal after 14 minutes when a James Coppinger corner was turned behind for a corner. The Rovers captain took the resulting corner, and his delivery was met by Joe Wright - he had a free header, but it went wide.
That kick-started a flurry of activity, with Blair and Houghton - who was deployed on the right of the midfield diamond - combining well before the latter whipped in a low delivery which was palmed away by home keeper Mark Oxley.
Michael Kightly fired wide a couple of times for the hosts, and Stephen McLaughlin put the ball wide after being played through by Marc-Antoine Fortune.
Oxley pulled off a brilliant double save as the game approached the half-hour mark. Blair’s cross from the right was met by John Marquis, who powered a header low towards goal.
The home keeper got down well to palm it away, then got up quickly to keep out Alex Kiwomya’s effort.
Those two chances in quick succession were the standout opportunities of the second period, with Tommy Rowe firing over from a free-kick and Baudry not able to get much direction on his header from another Coppinger free-kick.
Wright and Baudry also combined to keep the Shrimpers out at the other end, blocking efforts from Kightly and Joe Wright.
There were no changes at the break, and the second period was very similar to the first.
The first chance after the restart came five minutes in when Niall Mason won the ball in the opposing half then advanced on goal.
He had Marquis and Kiwomya either side of him, but chose to shoot with a strong low effort which Oxley kept out but spilled - unfortunately, from a Rovers perspective, the ball just would not fall to either of the forwards who were up with play.
Rovers had some luck down the right, with Blair and Houghton combining well. Michael Turner got in a particularly vital header from Blair’s cross with Marquis lurking.
Marko Marosi, starting his third game in a row, pulled off a great stop as the game reached the hour mark - getting two strong hands to Turner’s header following a corner.
Chances became harder to fashion out as the game entered the closing stages, and both managers started making changes.
Marquis almost caught Oxley out with a low free-kick which went just wide, while Anthony Wordsworth fired over for the home side.