The 23-year-old has a valid contract with Celta Vigo until June 2019.
Jonny Castro made 181 appearances across all competitions for Celta Vigo, scoring 3 goals and supplying 11 assists in return.
The 23-year-old is considered to be one of the best young left-backs in Spain.
Jonny Castro has represented Spain at Under-17, Under-18, Under-19, Under-20 and Under-21 level, winning 32 caps.
Eduardo Berizzo wants to sign a new left-back this summer and Jonny Castro is one of the names at the top of his wishlist. He has always been a manager who keeps his eyes on the most talented young players in Spain.
The Spain international is thought to perfectly fit the profile of defensive player Eduardo Berizzo wants to target in the summer transfer window.
Eduardo Berizzo will reportedly be handed a huge transfer kitty this summer and the Celta Vigo left-back is thought to be among the manager’s priorities.
Sevilla are in the market for just a handful of statement signings this summer who can improve the first-team.
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The Spain international would be a versatile addition for the Sevilla, having featured at left-back, right-back and in a centre-back role.
Celta Vigo are not in a position where they need to sell and would like to keep hold of the left-back, but right offer may force the club to consider a deal.
Jonny Castro has a release clause in his contract which stands at 16 million euros which would need to be met in full before Celta Vigo would allow him to leave the club this summer.
How strong that interest is and whether Sevilla will make a summer move remains to be seen but it is certainly one worth keeping an eye on.