This term Flash has had few chances but has struck twice with goals against Sheffield Wednesday (in the LDV) and Stockport after coming on as a sub.
Groves opted to play the 19-year-old ahead of Iffy Onuora for the visit of league leaders Plymouth, Mansaram repaid his manager with a committed performance that saw him pick up the man of the match award.
With Mansaram setting his own standards, Groves has told the player if he delivers that every week, he'll be an automatic starter.
"It's finding the consistency with Darren. He's a young lad still learning his trade but we all know he has the potential," Groves told the Grimsby Telegraph.
"But can he maintain the standards he's set? That's the question.
"He's got to fulfil the potential he's got and he's got to do it on a regular basis so that I can't leave him out."