But he also believes there is still plenty of room for improvement in his side.
Rovers showed a real clinical side to blitz struggling Bristol Rovers out of sight on Saturday with Mallik Wilks netting a brace and John Marquis and Tom Anderson also scoring.
McCann has regularly called on Rovers to be more productive this term and they certainly delivered at the Memorial Stadium.
“I think it was our most ruthless,” McCann said. “I think we can be more ruthless though and I said that to them at half time.
“I said the reason we were conceding chances was because the last little bits around the edge of their box have to be better. We have to control it better.”
The visitors went ahead when John Marquis received the ball in space 30 yards out on the left and picked his spot with a sweetly-struck right-footed shot into the opposite top corner that gave Jack Bonham no chance.
Two minutes before the break centre-forward Marquis turned creator as his header came back off the crossbar and Wilks pounced to force home the rebound from six yards.
The result was sealed when centre-back Tom Anderson was given the freedom of the hosts’ penalty area to rise unmarked and net with a downward header.
Five minutes later Wilks outpaced the home defence to complete a slick Doncaster break by shooting low past Bonham.
Bristol Rovers: Bonham, Partington, James Clarke (Bennett 31), Lockyer, Craig, Martin, O Clarke (Rodman 60), Lines, Sercombe, Nichols, Payne (Jakubiak 61). Unused substitutes: Upson, Reilly, Smith, Menayese.
Doncaster Rovers: Lawlor, Cummings, T Anderson, Butler, Andrew, Crawford (Rowe 69), Whiteman, Kane, Coppinger (May 79), Marquis, Wilks (Taylor 87). Unused substitutes: Marosi, Blair, J Anderson, Amos.
Referee: N Hair (Cambridgeshire).