Manly coach Geoff Toovey said he has apologised to a Bulldogs fan for a small altercation on his way down to the sheds at halftime of his side's 23-16 defeat at ANZ Stadium on Friday night.

"I reacted to some lunatic, I shouldn't have. A few words were exchanged," Toovey said post-game.

The third-year mentor was headed for the main tunnel when he responded to a comment made from a patron in the grandstand. Most officials commonly take the elevator or stairs behind the coach's box.

"It's quicker. I'd rather do that, I don't mind mingling with the fans and whatnot. But I said it's very silly of me and I apologised for reacting the way I did. I shouldn't have bit," he said.

Toovey would've been far more concerned with his side's lacklustre display against a Bulldogs side missing three key players, as well as a makeshift halves pairing of Josh Jackson and Tony Williams.

The hosts were also forced to play with 16 men for 74 minutes after starting prop Aidan Tolman aggravated a hamstring injury.

"It was very similar to the Tigers a few months ago. If you turn up against any team and you're not quite on your game, you're not going to win the contest," Toovey said. "I thought we were lucky to be in the contest tonight and we could've snatched it but we were just flat."

After their 24-16 statement against defending premiers the Roosters at home last week, Toovey said his side found it difficult to produce a repeat effort.

"It's one of those things. It's very hard to be up, I suppose, coming down from last week's pretty solid performance against the Roosters. Maybe there was a bit of a lull there and it caught us by surprise," he said.

But while his side were uncharacteristically off the pace for most of the match, the competition front-runners were still in it until Bulldogs skipper Michael Ennis scored a dubious try in the final minute.

"Let's not go there. There's four blokes out there, so anyway... It's no use me saying anything. They'll just say 'We got it wrong,' and that's the end of it," Toovey said.

"This is not because we lost tonight, [but] the rules have changed dramatically in the last few weeks. You saw State of Origin. The 10 metres has gone back to eight. The ruck control is just way down.

"I thought today was slow around the ruck and it obviously suited their game. Big forwards, laying in the ruck. They were very good at it. It's a very good game plan, and that's where they got us."