Source: Celtics give 2nd-rounder Demetrius Jackson 4-year, $5.5M contract

Point guard Demetrius Jackson, the 45th pick in the 2016 draft, will sign a four-year, $5.5 million contract with the Boston Celtics, a league source confirmed to ESPN.

The Boston Globe first reported the details of Jackson's rookie contract.

In earning an average annual salary of $1.38 million, Jackson will essentially be paid similar to the No. 23 overall pick, assuming that player earned 100 percent of the league's rookie scale. Depending on the structure of Jackson's deal, his guaranteed first-year salary could rival that of a pick in the late teens.

The deal might raise questions about why the Celtics would give such a lucrative contract to a mid-second-round selection. Just one year ago, Boston drafted Marcus Thornton at No. 45 and elected to stash him overseas in Australia to develop. He has yet to sign a deal with the Celtics.

Boston is essentially protecting its investment and utilizing available money to ensure Jackson stays under the team's long-term control. Second-round picks often settle for two-year deals at the minimum salary, which would pay only $543,471 this season. Teams are more commonly shunning these deals because over-performing second-round picks are in position to be signed away after two seasons, as drafting teams have only limited early Bird rights with which to retain them.

Jackson's deal will afford Boston the right of first refusal if he turns into a contributor at the NBA level. The Celtics executed a similar contract last season while inking 2015 second-round pick Jordan Mickey to a four-year, $5 million deal. Mickey, the No. 33 pick, got two guaranteed seasons at first-round money in exchange for being under the team's long-term control because the Celtics will hold full Bird rights by the end of his deal.

Jackson, who is 6-foot-1, had a quiet summer league debut for Boston. In eight appearances over stints in Utah and Las Vegas, he averaged 5.3 points, 2 rebounds, 1.3 assists and 1 steal in 16.6 minutes per game.

Boston appears deep at the guard spot, and Jackson's role could be limited in his rookie campaign, particularly if second-year guard Terry Rozier elevates to a rotation spot. Celtics president of basketball operations Danny Ainge had said earlier this month that the team was probably in the market for another ball handler to fill out its depth chart, and Jackson fills that role. He is probably ticketed to spend much of his first season with the Maine Red Claws of the D-League.

The Memphis Grizzlies drafted Deyonta Davis at No. 31 overall in June, utilizing a pick acquired from Boston, and recently signed him to a three-year, $4 million deal. That deal will make him a restricted free agent at the end of his three-year contract. The Celtics will have a team option for Jackson's fourth season, but he will be an unrestricted free agent at the end of his deal.