The Celtics’ future is almost completely locked in. Jaylen Brown agreed to a four-year, $115 million contract extension just a few hours before the deadline Monday, marking the first rookie-scale extension for Danny Ainge since Rajon Rondo’s 10 years ago. Brown’s deal is for $103 million guaranteed, with $4 million in likely incentives and $8 million in unlikely incentives, as reported by The Athletic’s Jay King.



Brown, who turns 23 years old Thursday, is now set to be one of the many faces of the Celtics franchise heading into his prime. He is signed on to start on the wing next to Jayson Tatum, who apparently will be looking for a max five-year deal a year from now, and Gordon Hayward, who could conceivably opt out of the $32 million he is owed next year if he has a big bounce-back season. Brown’s desire to re-sign with Boston was expected, but the surprise here is Ainge’s willingness to pay such a premium for a player who has not yet...