Right back is the last position we need a young "top quality" addition. Not even the Spanish giants have that kind of talent as backup in their ranks and we certainly don't, for literally every other position it'd make more sense to sign a guy of his age and pedigree
It's not that he wouldn't get any games here but that he's a) too good to play only around 20-30 games a season and b) he'll never come here. Bayern have been reported to be sniffing around as well and he'd be a starter for them