WARRIORS try-machine Aisea Havili could miss the start of the new Premiership season after recovering slowly from major surgery on his shoulder.

The Tongan wing went under the knife at the end of last season and, although he has returned to pre-season training, he cannot yet take part in full-contact work.

Havili has been visiting a specialist for regular updates but Worcester's director of rugby John Brain is not sure when he will be fully fit.

"It was a major operation on his shoulder," said Brain. "He could miss the first one or two games of the season.

"He's training but the issue is when he's able to take contact. There's a chance his playing debut for next season will be delayed, maybe until mid-September."

With the season getting under way on September 2, the fitness of a man who finished way ahead of the rest in the club's try-scoring charts last season will be a concern.

The rest of the news from Sixways is better. Long-term injury victims Chris Horsman (ankle) and Tim Collier (shoulder) are both expected to play a full part in the club's pre-season programme next month after recovering well from surgery.

Tom Harding and Mark Tucker, who had hip and groin operations respectively, are both expected to play in one of Worcester's three pre-season games.

Fly-half Shane Drahm, who was pulled out of the England Saxons' tour to North America, is recovering well after a minor clean-out procedure on the knee that was operated on last summer.

He will be able to resume running in two weeks. All of the squad have now returned to Sixways, with the exception of Tevita Taumoepeau, who is having an extended stay in New Zealand for personal reasons.

Worcester's summer tourists, including skipper Pat Sanderson and fellow back-row player Kai Horstmann, are reported to be in fine fettle as is new Argentina centre Miguel Avramovic.

He has arrived in Worcester after representing his country in their World Cup qualifying campaign.

Brain will make one further signing before the start of the new season with a hooker set to arrive around the middle of September.

"We are confident that everything is going well with that," he said. "We'll make that announcement at the start of the season but he won't be here for the start of the season."