United manager Russ Wilcox says it's up to the Iron's centre-backs to impress him as he prepares for the new season.
The Iron will start the campaign without the talismanic David Mirfin, who is set to miss the start of the season following a knee operation on Friday.That leaves Niall Canavan, Andrew Boyce, Luke Waterfall and Callum Howe battling it out for a place at the heart of the defence for the campaign curtain-raiser at Swindon Town on Saturday, August 9.
When quizzed by The Iron Player about the Canavan-Boyce partnership which has started the first two friendlies of pre-season, Wilcox said: "It's going okay. It's a work in progress.
"They've played two halves of two friendlies together, while Niall and David Mirfin played 45 games alongside each other last season.
"That gives me food for thought. I spoke to Andrew Boyce, Luke Waterfall and Callum Howe earlier on Saturday and told them that the opportunity is there.
"There is nobody in front of anybody at the moment. It's a case of showing what you can do and I'll make the choice from there."
Speaking after the 3-1 win at Gainsborough on Saturday, Wilcox said he was pleased with some elements - while he also thought there were things to learn from too.
"There's always a lot you can learn from every game," he added.
"You always want to score more goals, in any game you play.
"Again, credit to Gainsborough. It seemed a game where the next goal after half-time would be huge because if we had made it 3-0 it could have gone on, no disrespect, to a greater scoreline.
"When they pulled a goal back though it got their tails up and full credit to them.
"If it wasn't for a couple of saves from James Severn at the end then it could have been a draw."
See much more from Russ Wilcox, Matt Sparrow and Andrew Boyce on The Iron Player.