And that would be a step in the right direction for City after they have battled against themselves for the majority of the season, scoring plenty of goals but adding to the pressure by leaking goals too. Until recently.
City kept just one clean sheet in the first 21 rounds, but in the last three rounds they have beaten Sydney FC 3-0, Adelaide United 1-0 and Brisbane Roar 3-1.
Following the 2-0 loss by Western Sydney Wanderers to Melbourne Victory on Friday night and regardless of other results in round 25, a win over Wellington Phoenix at AAMI Park on Monday night will give City the competition lead with just two rounds to go.
"I think in the run-in to the finals Sorensen will still have moments when he has to act, but he'll be largely peripheral to the outcomes of matches," Bolton said.
"I think City are structurally so good at the moment that his work has mostly been done earlier in the season.
"He can put his hand up and say he's had a lot to do with where they are now and the fact is City have been fortunate to have had a keeper like that, but it's also great for him and the team if he's not having to do as much.
"He'll still have a big part to play come knockout competition when the championship is up for grabs in the finals, where it could come down to moments, and he's one of the best signings by any club in the A-League this season."
Bolton, who won two A-League championships with Sydney FC and two more in the old NSL, with Brisbane Strikers and Sydney Olympic, says he is delighted to see two goalkeepers who are 40 - Perth Glory's Ante Covic is the other - still thriving at this level.
"After last season, when Wanderers finished second bottom, it looked to me like Ante was slowing down," Bolton said. "He looked a bit slower in his movement and it wouldn't be a surprise, considering his age.
"I went through it myself and when you do start to slow down it happens pretty quickly, so I thought Ante was actually lucky to get another gig in the A-League this season. But he's just been a rock in Perth.
"I rate Ante highly and after his heroics at the Asian Champions League I was thinking that would be a great way to end your career for a guy I hugely respect, but I've been pleasantly surprised by how well he's done this season.
"If Perth go on and actually achieve something it's just another big achievement he can add to his long list and respect goes up again.
"He's been getting the job done and getting it done pretty comfortably and when it comes to knockout finals time his experience will be massive, because that's when the players with the big-game experience stand up to be counted.
"I think a foreign goalkeeper like Sorensen coming into the league was necessary for City if they were going to push for a title, because when you look at title winners you need a very good 'keeper and to be quite frank there are not a lot of young 'keepers coming through at the moment.
"So City made a really good move. If you don't have a good 'keeper, you can't really challenge for anything. Sorensen's been very good. He's made some big saves and he's won a lot of points for the club."
Sorensen has still had several moments he would like to forget, as well, but Bolton made the point that when you're forced to work as hard as Sorensen has been the odds of a slip-up increase.
"He been a busy man, overly busy, and I think his frustrations about how much work he has been getting, which are understandable, have been evident in his on-field reactions to his teammates at times," Bolton said.
"For the most part his form has been really good, making saves that actually affect the outcomes of matches, which is what the best goalkeepers should be doing.
"And now that City's defence is a lot more sound he's not getting as much work and that's been clear over the last three games. That's the way he wants it to be, I'm sure."
