The A-League is mature enough now to get rid of its salary cap, Wellington Phoenix manager Ernie Merrick says.

It is a strange thing for the coach of one of the more frugal teams in the league to say, but Merrick is of the belief that the current rules make the cap ineffectual.

"I just don't know why we bother with a salary cap, I think we've grown up, it's been 10 years now, let's just get on with it.

GETTY IMAGES Part of Andrew Durante's Wellington Phoenix contract does not count towards the salary cap.

"I don't know if it is a salary cap anymore, because there is a certain amount you can spend within the cap, then there are all these special little loyalty bonuses and first-year player bonuses - there are that many I have lost track - and then on top of that you can now really sign three marquee players."

READ MORE:

* Barbarouses eyeing titles with Phoenix

* Cahill set to sign for City

* New A-League boss named

* Phoenix play the player market

GETTY IMAGES Anthony Caceres was loaned out to Melbourne City after being bought by parent club Manchester City.

A-League teams can spend a maximum of A$2.6 million (NZ$2.78m) and must spend at least A$2.275m per year, but the rules are much more complicated than that.

Two "marquee" players don't have their salary counted towards the overall figure, and a guest player can also play 14 matches without their salary counting towards the cap.

Then you have homegrown and loyalty bonuses. That means A$150,000 paid to up to three players aged 23 or younger that have come through the club's youth system does not count towards the cap. Think Logan Rogerson and James McGarry at Wellington.

A percentage of the salary of the players that have been at the club for five or more consecutive seasons, up to A$200,000, does not count towards the cap. Think Andrew Durante and Vince Lia.

There are also mature age rookies, youth players, cap banking from the previous year and relocation expenses which can reduce your wage bill.

It's enough to send a manager mad.

"Why worry about a salary cap?," Merrick said.

"Why not let people invest big? It just makes the league grow rapidly. That's what's happening in the MLS [in the United States].

"I think it would present more of a challenge to our club to recruit well economically, to develop players, to have an academy where you're bringing players through and I think the challenge and the pressure is good for everyone."

Melbourne City, a club owned by English powerhouse Manchester City, have circumvented the A-League rule which prevents clubs from paying each other transfer fees for players.

Manchester bought Anthony Caceres from Central Coast Mariners in January and immediately loaned him to Melbourne. They have now loaned Luke Brattan to Melbourne, after signing him from Brisbane Roar last season, albeit with an unsuccessful loan move to Bolton in between times.

Melbourne are also rumoured to be offering Socceroos legend Tim Cahill A$4m per season to sign for them this season.

The moves irk some in the league, but Merrick sees the investment from Manchester's owners as a good thing.

"The rule has changed [for guest players] for them to be able to spend several million dollars on Tim Cahill, me personally, I think it's fantastic.

"To have a club like Man City buying a club like Melbourne City and investing in it, I think shows that this league is going places."

For his own side, Merrick said he had narrowed his chase for an import centre back to replace Ben Sigmund to two players.

"I'm pretty confident of getting a European player over the line and it's not a player in his 30s, it's someone in his 20s who is coming here for the right reasons and has a good CV behind him and the right kind of character that we're looking for."

The Phoenix are in China this week to play a friendly against Beijing BG on Wednesday at 10.30pm (NZ time).

* Sign up here for the Rio Olympics: Going for Gold newsletter