The Boston Celtics haven't given up on retaining Al Horford.

Shortly after multiple reports surfaced that the All-Star big man had a change of heart about plans to opt out of his contract and sign a long-term deal with Boston, Adam Himmelsbach of The Boston Globe reports the Celtics have been aware of Horford's discontent with current contract negotiations for days and still hope to bring him back in free agency.

Previous reports on Tuesday afternoon indicated Horford and Boston were so far apart in contract talks that hopes of the five-time All-Star continuing his career in green had completely evaporated.

Horford signed a four-year, $113 million deal with the Celtics in the summer of 2016. Though the unexpected struggles of Brad Stevens' team this season drastically altered the perception of its future, Hoford was broadly expected to remain in Boston going forward whether he exercised his player option or opted out to secure more long-term financial security at age 33.

Horford averaged 13.6 points, 6.7 rebounds, 4.2 assists, and 1.3 blocks per game during the regular season while fighting through nagging knee pain. Though his shooting numbers dipped after a strong start to the playoffs, Horford nevertheless proved his value as one of the league’s most versatile two-way big men during the Celtics’ disappointing postseason run, which ended in a five-game loss to the Milwaukee Bucks in the second round.

After news of Horford's likely departure emerged, The Athletic's Shams Charania reported that Danny Ainge and Boston's front office are preparing for a “strong scenario” in which Kyrie Irving also leaves the team this summer.