Abdel Nader was the No. 58 overall selection in the 2016 draft. (Getty)

The Boston Celtics and 2016 second-round selection Abdel Nader have agreed in principle to a four-year contract worth $6 million, league sources told The Vertical.

His agent, Cervando Tejeda, has been in discussions to finalize the rookie deal, and Nader plans to sign on Friday.

Nader, 23, was the No. 58 overall selection in last year’s draft and spent the past season with Boston’s NBA G League affiliate in Maine. He was the league’s Rookie of the Year, averaging 21.3 points, 6.2 rebounds and 3.9 assists.

When the Celtics selected Nader, both sides reached a draft-night agreement on a one-year stash in the development league. Nader received lucrative overseas offers but executed his plan with Boston to eventually join the 2017-18 team.

For the Celtics, incorporating Nader on the roster fills an open guard spot from the trade of Avery Bradley to the Detroit Pistons. Nader had an unheralded path in college at Iowa State and Northern Illinois, but has improved in multiple areas to become a potential rotation player in the NBA.

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