The Swans' 82-point drubbing of the Western Bulldogs, coupled with defeats to Collingwood and Adelaide this round, saw the Swans go a game clear on top of the ladder with two rounds to play. The Hawks sit second after their win over the Gold Coast on Sunday.
Longmire admitted it was one of the biggest home and away games the club has played in recent seasons, even if being minor premiers doesn't hold significant appeal.
"It is a big game for us, back at the SCG against another team at the top end of the ladder. It's an important game and a real challenge for us," Longmire said.
"Playing well against the best going around ... that's certainly what confronts us this week. The talent that Hawthorn has got in their team is enormous and we certainly respect that.
"It won't be easy."
The last time the clubs met, in round five at Aurora Stadium, the Swans prevailed by 37 points in a game that stamped them as real contenders. And Longmire is pleased his side enters their second meeting of the year in even healthier shape.
Against the Bulldogs, the Swans responded from a slow first term to slam home 23 goals to seven after quarter-time. The Swans had eight multiple goalkickers, and 14 individual goalkickers in a comprehensive performance.
After a lean patch of form, co-captain Adam Goodes performed well for the Swans with three goals and 22 disposals against the Bulldogs, while midfielder Josh Kennedy returned to his best form with 33 disposals (20 contested).
Longmire said the surprise defeats to the Magpies and Crows on Saturday night had been a warning for his side.
"Upsets can happen and [just] because you're in a game against a team outside the top eight, it doesn't mean you're automatically going to win," he said.
"You've still got to give really strong effort and we knew coming into the game it was probably one of, if not the, best Bulldogs teams named this year.
"We were concerned going into the game that we had to make sure we brought to the table significant effort."
Longmire said injured midfielder Jude Bolton was a slight chance to face the Hawks next week after continuing his extraordinary recovery from a knee injury, but that he might be held for the round 23 meeting with Geelong.
"He's running really well. We expect him to maybe progress that a little bit more to some agility work probably tomorrow (Monday) and maybe some training later in the week," Longmire said.
"And hopefully everything will go well for him, but it doesn't mean he's a certainty to play this week even if everything does go well.
"I'm not sure whether this week is the right time to bring him in."?
Callum Twomey is a reporter for the AFL website. Follow him on Twitter at @AFL_CalTwomey.
