By Duncan Johnstone

New Zealand boxer Joseph Parker got a double dose of good news today ahead of Thursday night's clash with Sherman Williams - his injured shoulder was cleared to fight and he got a significant boost up the world heavyweight rankings.

Parker passed a stern fitness test in Auckland today after visiting Dr. John Mayhew, who reassessed the injury following Friday's consultation after Parker hurt the left shoulder in training.

Dr. Mayhew inserted a cortisone injection into the problem area and declared he was comfortable with his condition. That was confirmed in the mind of the boxer and his trainer Kevin Barry when Parker got through four rounds of heavy pad work and weight-bearing exercise on top of sparring three rounds and skipping three rounds.

Then came the injection of faith from the WBA organization who updated their rankings today and lifted Parker from No.15 to No.11 in a division headed by world champion Wladirmir Klitschko.

Parker is the WBA's Pan Asian heavyweight champion. He is also ranked at No.14 by the WBO as their Oriental champion. He puts both belts on the line against Williams.

Barry said the rankings rise was a reflection of the work Parker had put in and the growing respect he was earning.

It was a boost for Parker's promotional team at Duco Events as they look to secure more meaningful fights in their drive to get the 22-year-old into the top 10.

He is unbeaten over 10 fights since turning pro in mid-2012, winning nine of them by knockouts.

"There are a lot of guys ahead of Joe who Joe is a lot better than. There's also some guys further down the rankings who would be difficult styles for us. So, as the coach, I don't put that much emphasis on the rankings," Barry said.

"But it is very good for the team at Duco ... the higher we move in the rankings it improves our chances of trying to get Joe into fights with other ranked guys."

Spreading Parker's rankings across the other organizations in the sport's alphabet soup of power is Duco's next challenge.

They are desperate to get him ranked by the WBC, the one organization freed of the Klitschko dominance after brother Vitali's retirement.

The WBC now have Canadian Bermane Stiverne as their champion, a fighter Parker has sparred with and looked more than comfortable against during his Las Vegas camps. That appears the easiest route to a genuine belt.

For now, taking care of Williams is the focus with Barry demanding an impressive victory.

Barry said the untimely shoulder injury hadn't affected their build-up work other than remove Parker's running work on Saturday when he had his left arm in a sling.

They remained on schedule and the game plan hadn't altered.

Parker was in a good mindset after proving himself today.

"Joe was at full power and had no pain at all," Barry said of the fitness test.

"I liked what I saw and was feeling. Joe hit really, really hard today. I told him not to hold back. I needed to be 100 per cent sure and so did he. He's feeling really good about himself, he's ready to go."

The injury isn't new. Parker had the same problem before his last win in New Zealand in July when he shrugged it off to knock out Brian Minto.

"We've been through this before. This is something we have been taking care of the last 12 months, we've had a few little niggles with it from time to time," Barry said.

"We have done a lot of strength work on it but occasionally the tendon inflames and it pinches and catches and causes a little bit of pain as we saw the other day."

Dr Mayhew "was adamant" no surgery was required.