After the Cleveland Cavaliers' physical examination of former Boston Celtics point guard, Isaiah Thomas, the organization has requested an additional trade asset, on top of the agreed upon deal which included Jae Crowder, Ante Zizic and the Brooklyn Nets' unprotected 2018 first round pick. 

Thomas' hip injury, which forced him to miss the final three games of last season's Eastern Conference Finals, raised concern about the timetable for his return and now the Cavs' are reportedly seeking one of the Celtics' young stars, or an additional draft pick. According to ESPN's Adrian Wojnarowski, Cleveland has targeted Boston's #3 overall pick in the draft, Jayson Tatum, though the Celtics have remained unwilling to include the former Duke Blue Devil in any of the trade negotiations.

The Cavs have also inquired about Jaylen Brown but Boston is resistant. The Celtics reportedly believe they were "completely transparent with Cleveland about where Thomas was physically, his rehab." 

Wojnarowski says, per NESN

“Now, Cleveland is going to try to inquire about a couple of the Celtics’ young players, Jaylen Brown, Jayson Tatum, who they tried to get in the original trade, that is very unlikely,” Wojnarowski said. “But Boston still has a war chest of future first-round picks of their own, and some picks they control from other teams, and Cleveland is going to try to get one more of those to finalize this deal.”

“Boston is resisting, and will initially at least, resist this idea. Boston believes that it was completely transparent with Cleveland about where Thomas was physically, his rehab. Cleveland’s version of this is that they didn’t realize how long Thomas could potentially be out this season, he’s in the final year of his contract, and obviously, that matches up with what will likely be the final year of LeBron’s current deal, and so there’s going to be a showdown between these two teams that may last a couple more days.”

In addition to their own future first-round picks, the Celtics have possible access to a plethora of future protected picks from the Los Angeles Lakers (2018), the LA Clippers (2019) and the Memphis Grizzlies (2019). Although, Yahoo Sports' Chris Mannix has said that the Celtics have drawn a line in the sand in the Kyrie Irving negotiations, and they're completely unwilling to trade Tatum, Brown or any more first round picks.