Gus Poyet has told Albion’s rivals it would take an “unbelievable” offer to tempt him to sell his skipper.

The Seagulls have rejected a shock bid from Barnsley for Gordon Greer.

Now boss Poyet has declared his defensive kingpin is not for sale – unless a massive offer comes in.

The Tykes are believed to have tabled less than £100,000 for Greer, who cost the Seagulls a reported £250,000 from Swindon two years ago and has been a key member of the side ever since.

Poyet said: “We are not surprised by anything but it is not an issue, it’s not our problem because he is not for sale.

“We can’t even talk about it until something massive comes in for someone, something that is incredible and we cannot reject.

“But he is the captain of the football club so it would take something incredible for us to consider.”

Greer scored against Barnsley when they visited The Amex in November and watched from the touchline as the sides ground out a season-ending 0-0 draw at Oakwell last month.

His style of play would suit that favoured by Tykes boss Keith Hill, who likes his teams to pass from the back.

But the offer caught even observers in South Yorkshire by surprise given that central defence is not seen as an area Barnsley urgently need to improve.

Greer is one of a host of players whose contracts expire next summer but Poyet said he would not be negotiating an extension as a result of Barnsley’s offer.

He added: “With the players under contract we are not ready to treat anyone differently.

“They are all in the same situation so there are not going to be any surprises.”

Poyet has confirmed he would be interested in bringing Joe Mattock back to The Amex but conceded he could face stern competition.

Mattock was released by West Bromwich Albion this week and a four-figure weekly wage is not thought to make him a comparative big earner at the Hawthorns.

Poyet said: “He is one of our options because we know him well.

“He was always on our list as a left-back cover or to challenge with Marcos Painter.

“We will consider him. But, yes, it could be difficult.”