The on-loan Aston Villa midfielder has found regular starts hard to come by since returning to the Keepmoat in the summer.
But with recent injuries and poor performances bringing reshuffles of the side, Calder is determined to take his chance.
“Every chance I have, I’m trying to take it,” said Calder, who will start tonight’s Checkatrade Trophy clash with Port Vale.
“Of course, when I came back I wanted game time. Everyone wants game time.
“But it was a new start for everyone and a whole different team.
“When I’ve played, I think I’ve done well enough.
“I wouldn’t say not playing is frustrating because you have to deal with stuff like that.
“We’ve been winning so many games so it’s been hard to change it. Last season when we weren’t winning, the gaffer could change it up.
“Everyone is doing what they have to do to get into the game.
“Obviously I want more game time but I know the circumstances of what I need to be doing to get that.”
Joe Wright is suspended for tonight’s clash after picking up two yellow cards in the previous two Trophy games.
Paul Keegan, Niall Mason, Alfie Beestin, Ross Etheridge and Liam Mandeville are all expected to start alongside Calder while Craig Alcock and Frazer Richardson will each be handed 45 minutes.
Andy Butler has been given the all clear following his back injury at Oldham but will not be involved tonight.
A draw will take Rovers into the knock-out stage while two points would see them secure top spot in the group and guarantee a home tie in the round of 32.