GUSTAVO POYET has told Connor Wickham that he must sign a new contract or Sunderland’s survival hero will be sold to prevent a substantial loss on the club’s most expensive teenage buy.

Wickham has so far failed to reach an agreement over a new deal after entering the final 12 months of the four-year terms he penned in 2011 after an £8.1m move from Ipswich Town.

Discussions between the player’s representatives and the club have continued during the summer, but a breakthrough has still not been found which has increased the chances of the striker being sold.

Poyet, the Sunderland boss, wants to know he has him on board for the new Premier League season after being impressed with his performances which helped the Black Cats preserve top-flight status in May.

The 21-year-old’s displays caught the eye of other Premier League sides, with Southampton, Leicester and Crystal Palace all credited with an interest in a player who will be allowed to move on next summer. As he is under the age of 24, Sunderland would be entitled to compensation.

But Poyet, who claimed he is “not worried”, does not want the matter to get to that stage. Having seen Jack Colback and Phil Bardsley leave at the end of their contracts this summer, he does want a repeat in 12 months time.

“For me, Connor's situation is clear,” said the Sunderland manager. “He needs to sign a new contract or we let him go – we sell him. There is nothing in between.

“He is an asset to the football club and we paid a lot of money for him. Last year he was a key part of us staying up and he was very important [to us].

“But he needs to realise that the club needs to look after the interests of the football club as well. I suppose that, one way or the other, we are going to have an agreement.

“Which one of those [sign a new contract or move on] is going to happen, I don't know – it is not my job - that is Lee Congerton's department.”

Poyet has been on the phone throughout his time in Portugal to hear developments in Congerton’s search for squad reinforcements. Defender Santiago Vergini is the closest to arriving, but Sunderland can’t really afford to lose another striker.

Fabio Borini could still join from Liverpool with a £14m deal agreed between the two clubs, but the departure of Ignacio Scocco means the pool of players Poyet has to call on is already a striker light.

Sunderland are still open to offers for a number of players and Real Betis remain keen to take Alfred N’Diaye back to Spain. The midfielder is reluctant to play in the Spanish Second Division, but he is also not guaranteed of a future on Wearside figuring here in Portugal.

Poyet said: “I need to make decisions. Diakite is not here, Cabral is not here, Danny Graham is not here, David Moberg-Karlsson is not here. And David Ferguson and Duncan Watmore, who have trained with us in pre-season, are not here either.

“If you think about the central midfielders I can play at the moment – Jordi Gomez, Seb Larsson, maybe Giaccherini – aside from Alfred, there is nobody else. The only other thing I could do is to change the system and play Liam [Bridcutt] and Lee [Cattermole], but I don't want to do that.”

*Sunderland have confirmed tickets for the club’s final pre-season fixtures against Real Betis and Udinese will go on general sale this week. The Black Cats take on Spanish side Real Betis on Thursday, August 7 before facing Italian club Udinese on Saturday, August 9. Both games are at Heritage Park, Bishop Auckland.