Ahead of the start of the 2015/16 La Liga season on Friday, AFP Sports takes a look at five of the most eye-catching transfers made during the close season:

Arda Turan - Atletico Madrid to Barcelona - 34 million euros ($37 million, £24 million) rising to 41 million euros.

Barcelona's ban on registering new players didn't prevent the Spanish and European champions from making a pair of big money signings in Turan and Sevilla's Aleix Vidal. Neither will be able to play until January, but the signing of the Turkish international after a hugely successful four-year spell with Atletico will add even more creativity to a Barca midfield shorn of the now gone Xavi Hernandez.

Jackson Martinez - Porto to Atletico Madrid - 35 million euros

Atletico invested the Turan money in reinforcing their forward line after the departure of Mario Mandzukic with Martinez following in Colombian compatriot Radamel Falcao's footsteps in swapping Porto for the Vicente Calderon Stadium.

Martinez struck 92 goals in 136 games for the Portuguese side, including seven in eight Champions League games last season, and a similar strike rate will make the 2013/14 Spanish champions contenders at home and on the continent once more this season.

Luciano Vietto - Villarreal to Atletico Madrid - 20 million euros

Atletico boss Diego Simeone's loyalty in signing a new deal with the club last season depended on him having more say in transfer dealings, so it was no surprise to see one of his former charges also arrive at the Calderon in Vietto.

Simeone gave the 21-year-old forward his professional debut when they were both at Racing Club in Argentina four years ago and he reminded his old boss of his potential with the winner as Villarreal became the first away side to win at the Calderon in La Liga for 19 months last December.

Evgen Konoplyanka - Dnipro Dnipropetrovsk to Sevilla - free transfer

Konoplyanka was the most serious threat to Sevilla's hopes of a return to the Champions League when the Andalusians overcame Dnipro in the Europa League final and a deal to land the highly regarded Ukranian winger could prove to be the most astute piece of transfer business in Spain this summer.

Samuel Castillejo and Samuel Garcia - Malaga to Villarreal - 16 million euros

The fight for the top four promises to be just as competitive as the record points tally it took Valencia to snatch the fourth Champions League spot last season. Villarreal look poised for another strong campaign after investing the money made from Vietto's sale in two of Spanish football's brightest prospects in Castillejo and Garcia.

Both were fundamental in Malaga's unexpected top-half finish last season and the fact they have chosen El Madrigal for the next step in their career rather than cashing in on a move to one of the top four could aid their chances of making the Spain squad for next summer's European Championships.