Hall had just five touches – all before half time – and managed one behind, but Roos said Hall, who entered the game with 10 goals from four matches this season, had been a good contributor.
"[His form has been] pretty good. He was really good last week and he was terrific against Hawthorn, so he's had a pretty solid season so far," Roos said post-match.
"He's the result of what happens up the field. If he's going to get one-on-one contests, as he did against Hawthorn, then he's going to win a lot of them.
"If he doesn't and our ball use is sloppy – and at times we went [inside 50] too slow – that makes it really, really hard for him, so I'm not concerned about Hally at all."
Roos said poor ball use from his side didn't help Hall's cause in the second half.
"I can't even think of a one-on-one contest after half-time that Hally and Scarlett were involved in. I don't even think there was an opportunity to mark the footy," he said.
"With all due respect to Scarlett, it was probably a pretty easy day for him after half time, because he didn't really have to do anything.
"It was more the result of just our poor decision-making and our poor skill execution."
But another star Swan, dual Brownlow Medallist Adam Goodes, was highly praised by Roos for his performance against the Cats, which included a team-high 27 disposals and two goals.
"Adam had a terrific game today, particularly later in the game, when he really turned the game and the momentum," Roos said.
