Grimsby have stepped up their bid to stay in the Football League by agreeing loan deals for midfielders Stuart Elliott and Dean Sinclair.
The Mariners sit one place above the League Two relegation zone and manager Mike Newell is hopeful Elliott and Sinclair will help his side climb the table.
Elliott has made just three starts for Doncaster this season after joining the Championship side in the summer from Hull City following a loan spell.
Sinclair, meanwhile, has figured only twice for Charlton since moving from Barnet in the summer of 2007 and had a loan stint at League One side Cheltenham earlier this term.
Both players are expected to go straight into the squad for the encounter against Morecambe at Blundell Park on Saturday.