The Mavericks still haven’t afforded former Villanova point guard Jalen Brunson a contract extension and he has made another leap this season. As The Post has reported multiple times, the Knicks have had Brunson on their radar. Brunson’s father is Rick Brunson — Leon Rose’s initial client when he started his sports agency business out of Cherry Hill, N.J. Thibodeau has had the elder Brunson on his staff for years before he rejoined the Knicks. With “T-Day’’ approaching in 3 ¹/2 weeks, the Mavericks are certainly capable of moving Brunson before the 2018 second-round pick becomes an unrestricted free agent. The Knicks already contacted the Mavericks sometime in the past about Brunson, an NBA source said. “They want him bad,’’ the NBA source said.