Xavi and Barcelona are not going to win the Champions League in such a short amount of time, but I'm sure Xavi and Barcelona will work hard to surpass what they've done this season. Barcelona is the best La Liga team this season, so they have to be strong enough and be able to compete in Europe next season.
Over time Xavi and Barcelona may return to the Champions League final, but as long as their finances are bad their efforts to get to the final will be very difficult. Some of the current players are good, but the performance of the team will not be the same every season so changes and improvements are needed.
Barcelona has all it takes to make it to the champions league final and win it. They are not there yet but with the right signings they can. In Europe this season, Barcelona were a bit unlucky. They lost a lot of their important players to injuries just before these big games. Even the second leg against Madrid in the Copa del Rey. Madrid would not have won that game if Barça players were complete.
This is the major reason Barça needs squad depth. Few injuries of first team players shouldn't spoil the whole season.