Madrid, Jul 7 (IANS): There were two important signings in Spanish La Liga as Atletico Madrid confirmed the arrival of Belgian international midfielder Axel Witsel on a free transfer from Borussia Dortmund while Real Sociedad signed Spain international Brais Mendez from Celta Vigo for a fee of around 14 million euros.

The 33-year-old Witsel is Atletico's first signing of the summer and will bring experience to the Atletico midfield, where he will compete for a place alongside players such as Koke, Marcos Llorente and Geoffrey Kondogbia, in the club's starting 11, on Wednesday.

"For me, Atletico is a big club. I want to continue playing at the top level and to play in the Champions League and that is why I am here," Witsel told the Atletico website.

Mendez has agreed on a six-year with Real Sociedad and the 25-year-old arrived in San Sebastian at around midday on Wednesday.

The player, who has made four appearances for the Spain national team, will cover the departures of attacking players, Portu, who has joined Getafe, and Adnan Januzaj, after the club surprisingly decided not to extend the contract of the Belgian international this summer, reports Xinhua.

Mendez usually plays in an attacking midfield role and scored 22 goals in 166 appearances for his hometown club, but the opportunity to play in Europe with the team from San Sebastian will help his chances of winning a place in Spain's squad for the World Cup finals.