Deco has faith in Luis Enrique
Barcelona lost the league title on the final day of the season after drawing at home to Atletico Madrid, who lifted the trophy for the first time in 19 years.
Argentine boss Gerardo Martino vacated his position following that result, which left the Spanish giants without a major trophy after reaching the quarter-finals of the UEFA Champions League and finishing runners-up to arch-rivals Real Madrid in the Copa del Rey.
Though, they did defeat Atletico in the Supercopa de Espana final at the start of the season in August.
But with Luis Enrique returning to Camp Nou, having played for Barca and coached their B team, Deco is backing the 44-year-old to bring back the glory days.
"Barca have had a poor season because they haven't won anything," said Deco, who won two La Liga titles and the Champions League during his four-year spell with Barca.
"But you can't write off a side which has astounded the world of football with their play and their titles.
"He (Enrique) is a young manager who knows Barcelona very well. Hopefully he can get us back to the level we are used to."
Deco also believes there are similarities between Luis Enrique and former coach Pep Guardiola, who also played together at Barca.
Guardiola was promoted from Barca's B team following Frank Rijkaard's dismissal, while Luis Enrique also worked with the club's reserves, though he went on to coach Roma and Celta de Vigo before returning to the club.
The Bayern Munich boss also oversaw a drastic overhaul of Barca upon his arrival, with the departures of Ronaldinho, Samuel Eto'o and Deco, which resulted in 14 trophies in four seasons.
Luis Enrique is expected to face a similar scenario, with an aging Barca team in desperate need of fresh faces as they aim to dominate world football again.
"They are different moments, because there were lots of changes with Pep. But with Luis Enrique, I'm seeing something similar to when Guardiola arrived," he said.
"However, we'll have to wait and see if he has that ability to do the same thing and believe in the players so they can get back on top of their game."