Left-back Cucurella had been an important player for Barca's second string, but they allowed him to depart on loan this season and Eibar have taken up the option to keep him, reportedly paying €2 million.
The 20-year-old featured 31 times in the league, nailing down a first-team role on the left flank as his energetic style of play and penchant for darting runs saw him catch the eye.
Cucurella scored his only goal in the 2-2 draw with parent club Barca on the final day of the season.
Although Eibar have triggered their option on Cucurella, Barca are rumoured to be planning on buying the player back in order to sell him on for a bigger profit, or alternatively to compete with Jordi Alba in the first-team squad.
Barca's buy-back clause is rumoured to be €4m.
If Cucurella is taken back to Camp Nou, then he could be understudy to Alba for some time.
He has also previously stated a desire to see out his playing days with the Blaugrana.
The 30-year-old has said of his future:“In football you never know, but I have repeated that my intention is to stay here.
“I’ve never seen myself away from Barcelona since being at Barcelona is my dream.
“Over the years, I have improved a lot and [now] I notice the affection of the supporters a lot more. I have always seen myself at Barcelona and my dream is to retire at Barcelona.”