More than 20 foreign players, led by former Costa Rica striker Paulo Wanchope and Paraguay's impressive World Cup goalkeeper Aldo Bobadilla, have been signed by the 20 clubs.

Wanchope has joined Rosario Central while Bobadilla will take over at Boca Juniors from Argentina's World Cup goalkeeper Roberto Abbondanzieri, who has left for Spain's Getafe.

Meanwhile, former Argentina internationals Juan Sebastian Veron, Crisitian Gonzalez and Ariel Ortega all return to the clubs where they began their careers.

Veron, 31 and still with plenty to offer, will line up with Estudiantes, Gonzalez joins Wanchope in Rosario and Ortega goes back to River Plate after nearly two years with Newell's Old Boys.

As usual, two separate league championships, known as the Apertura and Clausura, will be played in the 2006/7 season.

The 20 teams meet each other once in each tournament and there is no overall champion.

Boca, the country's most fanatically supported club, will be the team to beat after winning both championships last season.

However, Diego Maradona's favourite team will have to find a new coach to replace Alfio Basile, who has been appointed as the new coach of Argentina.

Basile, who took over with the club at a low ebb just over one year ago, will leave Boca on September 14.

The main challenge, inevitably, will come from Boca's great rivals River Plate under former Argentina captain and coach Daniel Passarella.

River, recently knocked out of the Libertadores Cup by Paraguay's Libertad, have now gone four championships -- or two seasons -- without winning a title.

Meanwhile, there is renewed hope at the other three major clubs, including Racing Club and Independiente, whose stadiums lie only 300 metres apart in the industrial neighbourhood of Avellaneda.

Independiente will start afresh under new coach Jorge Burruchaga, scorer of the winning goal when Argentina beat West Germany in the 1986 World Cup final, who has finally returned to the club where he was raised.

Coach Reinaldo Merlo is back at Racing, whom he led to the 2001 Apertura title to end a wait of 35 years for a major trophy.

Former Argentina captain Oscar Ruggeri has seen a major clearout at San Lorenzo, the other of the big five clubs, where a dozen players have left. Newcomers include Peruvian striker Roberto Jimenez and Bolivia's Joaquin Botero.

Other possible contenders include Velez Sarsfield, winners of the 2004/5 Clausura title, and Estudiantes, coached by former Argentina captain Diego Simeone.