He said, "You're never your best in round one, so it was a good first step but there is a lot to work on improving. That's especially when you play the Highlanders. What we've seen of them so far is they're another very improved team and we've got a six-day turn around, so we have to take that into account as we prepare for next week."
Cotter said it was a good start. There was content from the game they would go over and amend some aspects for the future.
"I thought the plan we had going into the game was more or less executed."
The start of the second half was one area of concern, especially after turning the ball over and the Drua scoring straight away.
"We need to get better than that. There are tweaks around the play, but they're a good team, better than last year, and they'll be very hard to beat in the islands.
"So, we're glad to get the win off them here. Overall I would say that the stress of going from friendly games to a competition game at home against a team that is very powerful and fast, I thought we were OK. I thought we remained reasonably composed."
Having scored five tries by halftime, they had appeared to go to sleep after the break, but they retained their discipline and made it difficult.
"That's something we need to keep on piling on good moments. It was great we pulled ourselves back into the game."
The scrum was good, apart from a couple of setbacks, which he felt were due to the pack losing concentration and not keeping the pressure on.
Withstanding the 23-phase opening by the Drua was a reminder that the side needed to start better.
At the same time, the side showed its defensive capabilities in scrambling.
"I thought they were going to score when they breached, they went wider than us and got down the far channel and their lock Ratu Rotuisolia, I thought he was going to go the whole way, but we got back and got the turnover. "
Cotter said that was a sign of character development and pride.
The Blues had kicked early but were giving the ball back to the Drua too easily.
"They were starting to put multi-phases in and the referee was looking at us a little harder around the ruck. So we thought we would hold the ball and we managed to string a couple of nice phases from the deep. That's something we need to encourage."
He was concerned about a lack of rhythm in their lineouts.
"I don't know whether it was the wind conditions, the heat, or whatever. But we didn't seem to be in position quickly enough, we were late and got caught out. They threw quickly but I just think we didn't quite get the rhythm right. We'll need to be faster against the Highlanders next week."
Blues captain and flanker Dalton Papali'i, who has tried to put on some extra weight in the off-season, said he felt the extra in the heat.
"It was not as hot as in Fiji last year but it adds another set of weight on the lungs. But it was good, we needed it.
"It wasn't perfect out there. We had our moments where we dominated, but we took our foot off the throat a couple of times, and you can't do that against a team like the Drua.
"We're a bit lucky they didn't execute some of their breakaways, but we have to be happy with our performance.
"I couldn't be more proud of the boys getting the first one under the belt because that's probably one of the games where you'll be nervous because it's the start of a new season.
"I'm happy with the performance, but never content. We always want to improve."
Papali'i said he felt the pack got a little hesitant because they were dominating the scrums only to take their foot off the throat, which allowed the Drua to get some momentum.
The side had to go deep defensively during the Drua's 23-phase opening assault.
"They were getting gain line pretty easy around the ruck with us and that's something we need to plug up very soon because a lot of teams will see that and use it against us. But you can't fault that 23-phase [defence]. It's starting off in that heat as well, and it's always hard to get your second wind as well."