Here’s a friendly reminder: The Boston Celtics essentially have $8.4 million in free money lying around and an open roster spot on which to spend it. So, what’s the holdup? Celtics president of basketball operations Danny Ainge on Thursday addressed the unique case of the Disabled Player Exception, an $8.4 million sum granted to the C’s after Gordon Hayward’s gruesome opening night injury that the team can use on any player signed, claimed or traded to Boston before March 10. It doesn’t sound like Ainge is in any rush to spend that extra cash, though. “We’re in conversations with people all the time,” Ainge said during an appearance on 98.5 The Sports Hub’s “Toucher & Rich,” as aired on NBC Sports Boston. “(The DPE is) a valuable thing, and yet it might not be used if we don’t need it. We’re not gonna just use it to use it. … Most likely, the better deals will be later in the season.” Here’s what Ainge likely is thinking: The Celtics are off to an NBA-best 18-4 start and don’t necessarily need to add a player now, despite their open roster spot. Better instead to wait until the NBA trade deadline on Feb. 8 to see which players are on the market, or try to scoop up a veteran who clears waivers after the deadline, like the Cleveland Cavaliers did last season with Andrew Bogut.