Barcelona and Atletico Madrid are poised to close the swap deal of the summer with Antoine Griezmann going back to his former club and Spain midfielder Saul Niguez moving to the Nou Camp.

The deal is a major coup for Diego Simeone as he tries to build on last season's title win but it also works for Barcelona, who will recruit the 26-year-old Saul who had interested several Premier League clubs this summer and cut their wage bill as they bid to register Lionel Messi.

Sportsmail understands that agreement is all-but finalised between the two clubs, but wage details still need to be worked out on both sides.

Chelsea, Liverpool and Juventus have shown an interest in Saul but Atletico are hopeful his swap with Griezmann will be tied up by next week.

Atletico want a straight swap deal while Barcelona want Saul plus cash in exchange for Griezmann with talks ongoing to reach a compromise.

Amid Atletico’s optimism there is also a background concern that Barca chiefs could yet have second thoughts after the Luis Suarez deal between the two clubs last summer.

Barcelona allowed Suarez to leave the Nou Camp for Atletico in a cut-price move, a decision that backfired as he scored 21 goals to fire Atletico to the title while Barca finished third.

Ultimately, Barcelona’s need to reduce their wage bill by moving on Griezmann, who earns in excess of £300,000-per-week after tax, is expected to be the defining factor and outweigh any worries about a repeat.

Griezmann had resisted leaving Barcelona after just two seasons and sources close to the player say he would not have left for any other club than Atletico, where he will reunite with Simeone.

Saul has been the fall-guy in the last two seasons at Atletico, constantly moved from position to position, and frequently used at full-back where he feels least comfortable. 

A move to Barcelona will put him back where he wants to be in a midfield group of four players – with Pedri, Sergio Busquets and Frenkie de Jong – contesting three positions. 

The move will also give him a chance of rebuilding his international career ahead of next year's World Cup.

Barcelona are desperate to announce a new contract for Messi but no they are still some way short of abiding by LaLiga's strict financial fair play rules on salaries. 

The Saul–Griezmann swap helps them because the midfielder will earn less than the Frenchman and register as a reduction in their bloated wage bill.    

Sportsmail understands that Messi has agreed to take a 50 per cent pay-cut to sign a new five-year deal with Barcelona.

The contract will see Messi stay at the Camp Nou until he is 39 and will help the club with their cost cutting following warnings from LaLiga president Javier Tebas who says their spending must continue to be reduced drastically before Messi can be registered.

Messi’s previous deal, which was worth in excess of £425million over four years, expired on June 30.

Barca president Joan Laporta has remained determined to convince the club talisman to stay after Messi attempted to quit the club last summer.

Despite becoming a free agent and previous interest from Paris St German and Manchester City no talks with other clubs took place in recent weeks.

Messi is on holiday with his family after leading Argentina to Copa America glory over Brazil last weekend, his first major trophy with his country.

The 34-year old has been with Barcelona’s academy since 2000 amassing 778 games and scoring 672 goals.