Manchester City are ready to pay the €50m (£39m) release clause to sign the French defender Aymeric Laporte from Athletic Bilbao as Pep Guardiola steps up his recruitment drive for next season.

City confirmed the signing of the Germany midfielder Ilkay Gündogan from Borussia Dortmund on Thursday for around £20m but with concerns over the long-term fitness of captain Vincent Kompany, central defence is seen as a major priority. As revealed by the Guardian in April, Laporte has been identified as Guardiola’s preferred target despite the defender being ruled out until August with a broken leg and dislocated ankle.

City are understood to be preparing a contract offer for Laporte and his agents – former Spain internationals Carles Puyol and Iván de la Peña – before submitting their bid to Athletic.

Having turned 22 last week, Laporte has been a regular for the Basque club since 2013 and has now played more than 120 games in La Liga. He is also predominantly left footed – a trait that is believed to have been made a priority by Guardiola and the sporting director, Txiki Begiristain.

Laporte, who moved to Athletic as a 16-year-old, has signed four contract extensions since December 2013 as his status as one of the world’s best young defenders has grown.

His potential signing would take the club’s spending on central defenders over the last two years to almost £110m, having spent £42m on Eliaquim Mangala in 2014 and £28.5m on Nicolás Otamendi last summer. City also already have the highly rated Belgium defender Jason Denayer on their books, who is expected to be given a chance to prove himself in the first team squad after spending the last two seasons out on loan.

City are also understood to be interested in signing 16-year-old striker Abel Ruiz from Barcelona after his impressive performances in the Under 17 European Championship last month, when Spain were beaten in the final by Portugal. Ruiz, who has also been tracked by Arsenal in the past, is believed to be open to the move having not signed a contract which was offered to him in March.