"When we acquire Evan, we don't acquire him with the idea that he's going to be with us for just this year," Ainge told reporters. "We acquire him with the idea that he potentially could be here for a long time."
Fournier was enjoying a strong season with the Magic before the deal. He averaged a career-high 19.7 points along with 3.7 assists, 2.9 rebounds and 2.8 threes across 26 appearances. The 6'7", 205-pound guard was shooting 46.1 percent from the field, including 38.8 percent on three-point attempts.
The Frenchman's only issue during the season's first four months has been injuries. He was sidelined twice by back spasms and also missed time with a groin injury.
If Fournier can stay healthy, he should provide a major boost to the Celtics backcourt for the remainder of the campaign, though his offensive usage won't be quite as high in Boston as it was in Orlando.
His acquisition represented a worthwhile flier for the C's, who are seeking a spark as they rank eighth in the Eastern Conference with a 21-23 record.
Looking ahead, it's unclear whether Fournier is willing to sign an immediate extension or if he wants to at least test the free-agent market in the summer.
John Hollinger of The Athletic reported Boston could use its Bird rights to give him a three-year deal worth around $50-55 million right away.
Fournier could also bet on himself and attempt to further increase his value during the stretch run of the regular season and the playoffs by helping the Celtics, who made the Eastern Conference Finals last year, return to form.