“That’s what it’s all about,” said McCann after a thrilling encounter.
“I said it to the players – that’s the way I play. We’ve come to a team that are probably one of the best teams in the league at home and Chris Powell’s record speaks for itself, and we absolutely dominated them in the second half.
“Of course we had to ride a wave for 35 minutes in the first half when we were relying on our back four, relying on Marko Marosi, who was unreal and who pulled us out of it.
“When you’ve got the threat that we have at the other end of the pitch with Wilks and Marquis you can hurt teams.”
Rovers netted three goals in 19 minutes in the second half, but they were indebted to a fantastic goalkeeping performance from Marosi.
The Slovakian denied both Ben Coker and Simon Cox in a first half dominated by the Shrimpers.
Rovers took control and opened the scoring in the 51st minute with John Marquis firing home from close range.
Six minutes later Mallik Wilks sent a 20-yard shot into the bottom right-hand corner before a tame efort from Tommy Rowe trickled in to make it 3-0 in the 70th minute.
Southend responded with Tom Hopper reducing the arrears in the 75th minute before Marosi did well to deny Sam Barratt and Sam Mantom. However, he was beaten again in the 86th minute by substitute Theo Robinson.
Southend United: Oxley, Demetriou, Lennon, Turner, Coker, McLaughlin (Barratt 65), Hyam, Mantom, Kightly (Dieng 73), Cox (Robinson 65), Hopper. Unused substitutes: Bwomono, Bishop, Klass, White.
Doncaster Rovers: Marosi, Mason, Wright, Butler, Andrew (Amos 66), Whiteman, Crawford (Blair 77), Rowe, Coppinger (Kiwomya 59), Marquis, Wilks. Unused substitutes: Kane, Lawlor, Anderson, May.
Referee: C Hicks (Surrey).