Rovers ended a run of six games without a win as goals from Matty Blair and Ben Whiteman saw them beat an impressive Luton outfit who may feel hard done by as they went away empty handed.
McCann's side were forced to hold on for long periods of the second half and, in doing so, earned the praise of their boss.
"We are showing our steel at the minute," McCann said. "We're showing both sides of our game.
"We showed our quality against Portsmouth and Peterborough and we showed our steel in this one and that is the side you need if you are going to challenge in this league.
"That is four unbeaten in the league - two against the top two and one against a team I think will be in the top six without a shadow of a doubt."
McCann was full of praise for Luton after the game and expects the newly promoted Hatters to mount a strong challenge for promotion this season.
And he said Rovers' success in resolve made the winÂ all the more pleasing.
'The first 15 minutes we have started really well,' he said.Â 'I thought we could have scored another couple of goals in that spell.
'We sat back a little bit, they came into the game and we found it difficult.
'It was just a matter of time before they were going to score. Wave after wave of attacks.
'We sounded it out, made a couple of changes at half time, played a diamond with James Coppinger as a ten, and I thought for 25 minutes we looked the better team.
'Then Luton came strong again but we held on and showed that different side of our game.'