According to Miguel Rico our other LB options that we had on the list but we didn't buy.
Gayá, Adrian Marin, Theo Hernandez, Ricardo Rodriguez, Sergio Escudero,Jonas Hector,Wendell, Raphael Guerreiro.
Hector and Escudero didn't make the final cut because Robert and Lucho thought they didn't have what we were looking for in a Barca style LB. Raphael Guerreiro didn't want to sit on the bench here and felt like Dortmund's offer was better for his development.
Theo Hernandez was to young and "Raw" to be our second choice back up for Alba and could also be the reason we didn't go for Adrian Marin either. what was left was Digne,Wendell,Rodriguez and Gaya.
While Rico didn't give an explanation in regards to Rodriguez I think he wasn't willing to come here and sit on the bench either. he's certainly good enough to be a starter for most clubs out there. Gaya I don't think even with Valencia's financial issues were willing to let him go so easily without a hefty fee.
Wendell has a contract until 2019, and Leverkusen wanted a lot of money for him as well. from what I've read from various fans he wasn't really that great for Leverkusen last season.