Midfielder Harris and defender Watt have performances to support their inclusion after playing crucial roles in the Roos' upset of the Hawks in round 13 last year.
Harris rebounded strongly from a disappointing match against Fremantle while Watt was used as a floating backman to keep Hawthorn forwards Lance Franklin (one goal) and Jarryd Roughead (two) out of most contests.
"They'll be around the mark," Laidley said of Harris and Watt from Arden Street on Thursday morning, adding that replacements may need to be found for veteran Adam Simpson and defender Daniel Pratt, who are in the spotlight following Wednesday's video scandal.
North has a reasonable record against the 2008 premier and should have beaten the Hawks on both occasions last year, but surrendered a comfortable three-quarter time lead in round three.
Far from the side that beat Geelong in the grand final, Hawthorn fell short in its rematch with the Cats and crashed to the Sydney Swans at ANZ Stadium last weekend.
"They've been crucified by injury," Laidley said. "They have been unable to get their best side out on the park but they've still got one or two excellent midfielders.
"They've got two blokes up forward (Franklin and Roughead) who can cause some havoc and they're still a very, very good football side. [They're] well-structured [and] well-coached."
Asked whether he'd rather encounter a Hawthorn side with two wins or two losses from its opening rounds, Laidley said he hadn't given it a lot of thought.
He was also tight-lipped on his plans for the Hawks' rolling zone after having some success in breaking it down last season.
"I might have to come up with something different," he said.
However, Laidley saw promise in his side's efforts in the 15-point loss to the Western Bulldogs and hopes his players can maintain their intensity.
"We had a good win against Melbourne in round one and we had every opportunity to win last week," he said. "We probably made some mistakes and missed opportunities in the last four or five minutes and we couldn't quite get them.
"There were five points in the first quarter, we hung around all day, we came late but we couldn't quite get there.
"The football we played was reasonable. I thought our intensity was up and we need to make sure it's up this week as well."
