The Eredivisie champions signed the Spaniard on loan in July last year, but the 23-year-old has struggled to make an impact at the Amsterdam Arena.
As part of the deal, Ajax did have the opportunity to extend Bojan's stay by another season, but they have decided to allow him to return to Barca, meaning that he will not join the team at their training camp in Indonesia.
Despite the decision, Bojan was quick to express his gratitude to the club following a season that has seen Ajax claim a fourth consecutive league title.
"Thanks AFC Ajax for such an amazing year," Bojan posted on his Facebook page.
"I'm so grateful to all of you for the support and affection, I think it has been a very enjoyable season and we've achieved two important titles.
"This morning we've decided together with the club that the option that best fits is to continue training during next two weeks at Toekomst (Ajax's training gound).
"Wherever I go in the coming years I'll take with me the philosophy, style of play and passion for this sport you have. You are and always be in a very important part of my heart."
