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.
Woj also goes on to say that the Celtics thinking about trading for Leonard could have changed since the trade deadline, with the performance of Jaylen Brown and Jayson Tatum following Kyrie Iriving's season ending injury, leading Boston to a fairly improbable run to the Eastern Conference Finals.
Any trade with the Spurs would surely cost Boston at least one of Tatum or Brown, along with other assets. Leonard played only 9 games this season for the Spurs.