West Ham United's co-owner, David Sullivan, has warned that Scott Parker is the only player the club would not consider selling during a summer shake-up at Upton Park.

Sullivan, along with his boardroom colleague David Gold, is beginning preparations for a busy off-season in the transfer market after the club effectively ensured their Premier League survival with Saturday's 3-2 win over Wigan Athletic. They have already made a written bid in the region of £4m for midfielder Graham Dorrans, which was turned down by West Brom today.

"Other than Scott Parker, there is not a player we wouldn't sell if it was the right bid," said Sullivan. "Scott will not be sold and we will be buying more than we are selling. There will be no fire-selling and we will enhance the squad, not diminish it.

"We will have to shake up the pack because there is no point kidding ourselves otherwise we will be in the same position next year – the table doesn't lie."

But, while he expressed a wish to keep the captain, Matthew Upson, Sullivan made no such guarantees over the former Birmingham City defender – or, for that matter, his international colleagues Robert Green and Carlton Cole.

"We will make [Upson] a proposal for a new three-year contract," he said. "We would give him an offer of a comparable level to what he is on now, which he may or may not want to take.

"But Upson has a year to go so if we get a good offer we will take it."