He reasons that the movement of the Italian side meant high concentration was a must and any slip ups invariably punished. Lazio slipped through the gears after going two goals down and squared the match with some incisive attacking play.
"This was good opposition and required more mental toughness than physical because their movement was so good and they are such good players you can't switch off for a second," said Dean afterwards.
"It's good for fitness, but all about concentration.
"Their full-backs pushed on a bit more in the second half and caused a bit of a problem. In the first we dictated the game and got off to a good start.
"The goals came at a good time for us and if we can maintain that sort of form for 90 minutes we'll be well up there I think."
On his opening goal Dean admitted that he didn't think his goalwards lunge would reach the ball.
"I was up there for the corner, it was a case of staying round the back and waiting for it to come back in.
"I didn't think I was going to get there, but I stretched out and managed to get on the end of it."
Goalscorer Dean Richards said that facing Lazio was more a mental challenge than a physical one.