Barça promised it to him last season to avoid his exit
There is some move to be seen in Barça's goal. According to Esport 3, the starting goalkeeper for the coming season will be the German Ter Stegen. This is what the Board promised him to avoid his departure from Barça, since the German player is said to have received an interesting offer from Manchester City. Ter Stegen is a bet on the club's future, but this decision will surely not be well received by the other keeper of the squad, Claudio Bravo.
Having been the starter during the two past seasons, the goalkeeper has shown a good level with the team and also with the Chilean national team, with which he has won two Copa América since he joined Barça. Nevertheless, the promise made to Ter Stegen would put Bravo on the bench, a situation he will hardly accept. In that context the name of Manchester City is coming back. Pep Guardiola is not convinced by the performances of his current keeper Joe Hart and he's said to be interested in signing Bravo, if the latter feels unhappy.
Given the situation, and aware it will be impossible to hold on those two international goalkeepers, Barça might have looked for an alternative choice for the position of second goalie. The one they are said to have chosen is Pepe Reina. Very experienced goalkeeper, he already had that role in Bayern and would accept to be in the shadow of Ter Stegen.