All Black Frizell was left out of the side last week after his alleged involvement in a Dunedin bar assault.
Dermody explained: "Last week he was not quite in the right head space to play for us, so we decided to leave him out. It was the right decision. He seems energised now, and ready to go again," he said.
Five-eighths Josh Ioane's return to the bench from his ankle injury was ahead of schedule, and he had been working hard in his time out of action.
“He has done a lot off field. He has almost personal-best skin folds, so that shows a change of mindset for Josh. He is really starting to work on his off-field game as well.”
Working on a more clinical approach would be the goal for the Highlanders against the Force. That was lacking in their win over the Reds when the Highlanders were guilty of letting pressure off.
But, overall, he was happy with how the side performed.
"We're happy with round one. We try not to read too much into the press around the draw and how we got lucky. We just dealt with the team that was in front of us. I'm happy with how we executed the game plan for extended periods.
"If we can lose those loose moments in games, that is the way forward for this team," he said.
The Force showed in pushing the Chiefs within a conversion of defeat that they were a capable side, and Dermody said they had a strong culture.
"They've fought back from not even being in the competition, to be now pushing every team late in games.
"I think that shows the good job they have done. They are not easy. They are a quality team with a good spine," he said.
Hooker and captain Ash Dixon said they were excited to be renewing contact with the Force after nearly five years.
Dixon said head coach Tony Brown, who is working with Japan ahead of the Test match with the British & Irish Lions, is still involved in their preparations each week.
"He's still very much part of our group, and he's working well with Dermo [Dermody], and Dermo is doing a great job at getting the boys together and making sure we're on the right path.
"There's no real difference, it is just that he's not here, so the boys have just cracked on with it," he said.
The challenge in Perth would be backing up their win over the Reds, something the side had not done this season. He was looking forward to seeing if they had learned some lessons on that front.
The Force would be tough. They were like the Highlanders in having players who came from all around Australia to create an environment they had all bought into.