I really don't see the problem in this, we're losing both Sagna and Zabaleta this window, that means we need a full back and a back up full back, how can we be expected to pay 30+m on a starting full back then also pay for a back up that would be a fair chunk of our budget gone on one position surely it is better to retain Navas as he is a cheap option so we have more money to use on other areas of the pitch that are in desperate need of reinforcements. After all, it's not like he'll be starting 30/40 games a season, he might not be the most technically gifted player ever to grace the pitch but he puts a shift in and could do a job a few games a season.