The twenty seven year old is still in China waiting for confirmation of his visa to come through.
The utility player had hoped to be at Carrington for the start of pre-season training but could now go directly to Thailand to join the squad there.
The China international who was sidelined for most of last season as he recovered from knee surgery had been following a pre-planned fitness programme in China during the summer.
"We are waiting for Jihai Sun as he still has not got his visa cleared. If that doesn't happen by Thursday we will probably send him straight into Thailand," explained the boss.
"He was probably eighty per cent fit by the end of last season. Rather than carry him on through the summer at Carrington he went home to spend time with his family.
"He is currently training with his old club which is beneficial for us as he waits for his visa."
The manager confirmed that Richard Dunne who underwent surgery at the end of last season will be fit for pre-season.
Geert De Vlieger and Trevor Sinclair will also feature having spent the last eight weeks training at Carrington.
"Richard joined in pre-season training from day one along with Trevor Sinclair and Geert De Vlieger.
"Geert and Trevor trained very hard during the summer. Every day that I was in they were also in.
"They have worked hard and look fully fit and ready to go. That is a great credit to the pair of them."
Nedum Onuoha and Nicky Weaver remain the two, "long term," injuries though the manager is hoping the duo will return for the start of the new campaign.
The defender is recovering from a hamstring tear while the City stopper is making good progress after an operation on a broken bone in his hand.
"They will be out for a while yet but we are hoping to have them both back for the start of the season," added the manager.
David James and Kiki Musampa will join in pre-season training for the first time later this week.
The manager handed them an extra week off as both had been on international duty during the close season.