Fiorentina have confirmed Marcos Alonso has completed his move to Chelsea. The former Sunderland and Bolton defender returns to the Premier League having signed a five-year deal at Stamford Bridge, arriving for a reported fee of £23m.

Elsewhere at the Premier League club, Colombia international Juan Cuarado has finally sealed his protracted return to Juventus. The Serie A club have confirmed the winger's return on a three-year loan deal, with the Serie A champions paying an annual fee of €5m.

Alonso's move was initially confirmed by Fiorentina via an official statement before Chelsea made a formal announcement.

"I'm very happy. It's a step up in my career and I think this is the perfect place for me to continue developing. It's time for me to win some titles," the 25-year-old told Chelsea's official website.

Marcos Alonso
Alonso returns for his third spell in the Premier League Getty

"It was an easy decision for me to make when I heard the club were interested in signing me. My family and close friends know Chelsea is the club I have dreamed about playing for so I'm really excited about the challenge and I'm looking forward to working with my new team-mates."

Alonso returns for his third spell in English football, having had a three-year stint with Bolton from 2010 to 2013 before returning to join Sunderland on a six-month loan deal in 2014.

The former Real Madrid starlet becomes Chelsea's fourth signing of the summer transfer window following the arrivals of Michy Batshuayi, N'Golo Kante and Eduardo.

Chelsea are also on the brink of resigning Brazil defender David Luiz from Paris-Saint Germain. According to Le Parisien, the 30-year-old has travelled to London to complete a deal they expect to be formally announced in the coming hours.