The following is an excerpt from an article by Adrian Wojnarowski:
The Boston Celtics made a trade offer to San Antonio before the February deadline, but the Spurs turned it down --- and never made a counterproposal, league sources said. San Antonio wasn't willing to discuss deals for Leonard in February. So far this spring, the Spurs remain resistant to trades.
If reconciliation talks don't go well with Leonard, San Antonio has time to reconsider that stance. For example, Boston has the most appealing assets: starry young players and Sacramento's No. 1-protected 2019 first-round pick.
Only four months since the trade deadline, the Celtics find themselves in a different organizational space. GM Danny Ainge can stay on course with forwards Jayson Tatum and Jaylen Brown on rookie contracts, sparing Boston the financial pressure of re-signing two maximum-contract players with injury histories -- Kyrie Irving and Leonard -- in 2019.
Boston could still consider Leonard on a distressed, discounted deal -- the way it secured Irving last summer -- but that has become a far less likely scenario than keeping its young core.
http://www.espn.com/nba/story/_/id/23770525/what-next-kawhi-leonard-san-antonio-spurs-nba-free-agency-trades