Sunderland could head off on their pre-season trip to Portugal with no new faces on board as they refuse to be held to ransom in the transfer market.

Chairman Niall Quinn and manager Roy Keane have spent the close season pursuing targets and attempting to negotiate deals with their clubs, but to date they have seen few tangible results.

Keane and his players are due to fly to the Algarve at the end of this week for friendlies against Sporting Lisbon and Vitoria de Setubal with the start of the new domestic season just a month away.

With Stephen Wright, Andy Cole, Stanislav Varga and Ian Harte having all been released and a series of other players told they can leave, the squad is thinner than the manager would like and the extra quality he hoped to recruit this summer is yet to arrive.

In addition, Kenwyne Jones' injury situation — Sunderland are yet to confirm the extent of the damage to his knee ligaments or his expected recovery period — has increased their need for a top-class striker.

The Black Cats have been linked with a list of potential signings which has grown almost by the day, although the perception that they have money to spend — Keane has hinted he could invest in excess of the €55 million he spent of new players last season — has perhaps not helped.

Their long-standing interest in Reading midfielder Stephen Hunt appears to be waning with the relegated Royals holding out for at least the €6.25 million they were offered for his services by the Wearsiders in January.

But after being accused of paying over the odds for their summer signings last season, Sunderland are adopting a pragmatic approach this time around and are sticking to their own valuations.

Keane has shown in the past that he is prepared to be patient to get his man — his dogged pursuit of Hearts' Craig Gordon last summer eventually proved successful, although he did eventually have to hand over a British record for a goalkeeper, €11.3 million, to get him.

However, he has also shown himself willing to pull the plug on a deal if it is not right for the club, ending his efforts to persuade then Preston striker David Nugent to head for the Stadium of Light as the player stalled on making a decision.

Ultimately, the manager's shopping spree could come down to a game of brinkmanship as he waits for the sellers to blink first, although he knows the clock is ticking.