The Knicks agreed to a two-year, $31 million deal with free-agent power forward Bobby Portis, his agent, Mark Bartelstein, told SNY's Ian Begley.
Portis joins Julius Randle and Taj Gibson as the Knicks' signings after they lost out on both Kevin Durant and Kyrie Irving.
The 24-year-old Portis averaged 14.2 points and 8.1 rebounds in 50 games with the Chicago Bulls and Washington Wizards last season.
Earlier Sunday, the Knicks agreed to a three-year, $63 million deal with Randle and a two-year, $20 million contract with Gibson.
But New York made those moves after both Durant and Irving agreed to four-year near-max contracts with the Brooklyn Nets.
Knicks president Steve Mills released a statement prior to Portis' agreement expressing his optimism in the franchise's rebuilding strategy amid missing out on Durant and Irving, two of the game's biggest stars.
The Knicks entered free agency with approximately $70 million in cap space. With the three signings thus far, they have around $23 million remaining in cap room.