Arsenal say they have secured "one of the strongest young defenders in European football" after completing the signing of Cristhian Mosquera from Valencia for an initial fee in the region of 15m euros (£13m).

The 21-year-old has joined the Gunners on a five-year contract, which has an option for a further 12 months.

Mosquera can play at both centre-back and right-back and will fill the gap in the squad left by the departure of Takehiro Tomiyasu, who mutually agreed to terminate his contract earlier this month.

"I couldn't let it pass me by. I'm joining a historic, massive club. When you arrive here with your family, you really feel the greatness of the place," Mosquera told the club's website.

"My career has moved faster than I expected, and I've had to mature fast. Coming here is a chance to keep learning and improving."

The Spain Under-21 international joined Valencia in 2016 as a 12-year-old before making his first-team debut in 2022 when he became the youngest centre-back to play for the club.

Mosquera made 90 appearances for Valencia and was a regular for them last season, playing the full match in 37 of the club's 38 La Liga games as they finished 12th.

Manager Mikel Arteta described Mosquera as a player with "exciting talent and enormous potential" while sporting director Andrea Berta hailed the defender's long-term prospects.

"We identified Cristhian as one of the strongest young defenders in European football, and he is an important signing for our future. Cristhian is a versatile defender who will strengthen our squad," Berta said.

He follows Martin Zubimendi, Kepa Arrizabalaga, Christian Norgaard and Noni Madueke in being added to Mikel Arteta's squad this summer, with Viktor Gyokeres also close to joining the Gunners.

Mosquera is set to join up with the Arsenal squad on their pre-season tour in Asia as he had already been given permission to travel by Valencia before the deal had been confirmed.

Arsenal beat AC Milan 1-0 in Singapore in the National Stadium on Wednesday and take on Newcastle United at the same venue on Sunday.

They then travel to Hong Kong to play Tottenham Hotspur before returning to London.

Mosquera gives availability and versatility - analysis

Arsenal have secured the signing of Mosquera and have added what they feel is a young defender with quality to add options to their backline.

He has played senior football for two seasons, and in 2024-25, he not only played the most minutes of anyone in the Valencia squad but also the second-most of any outfield player in the entire La Liga.

That type of availability is important to Arsenal manager Arteta, who will be hopeful to avoid the injuries which caused so many issues for him last season.

Alongside the availability, Mosquera can play across every position in defence, adding versatility to a strong Arsenal squad.

The 21-year-old may take time to adapt to the league and country, but with a large contingent of Spanish speakers at Arsenal, the process of settling in should be a lot easier.