The Nets are finally giving David Duke Jr. a well-deserved standard contract, league sources told the Post.

After spending his rookie campaign and almost all of his second season as a two-way, Duke Jr. is being converted to a standard deal.

The move was expected to be made official on Friday.

The Nets did the same thing late last season in converting two-way rookie Kessler Edwards to a standard deal.

Brooklyn had a space open on its roster because of another move, the departure of little-used Moses Brown after the expiration of his 10-day deal.

Considering how well Duke Jr. has developed and how little Brown has played — and how unlikely he was to feature in the playoffs — it was a logical move by GM Sean Marks.

Teams don’t generally play big in the postseason, and bringing in a free agent center cold off the street to try to get up to speed was never likely.

And the Nets already have been more effective playing smallball lineups when starting center Nic Claxton is off the floor, so the second-year combo guard makes sense.

Duke Jr. made the Nets on a two-way as an undrafted free agent last season, averaging 4.7 points in 27 games as a rookie, including seven starts.

Following a solid performance in Las Vegas Summer League, he had hoped to earn a standard contract, but ended up back on another two-way.

This season Duke Jr. averaged 3.1 in 21 games this season, shooting a solid .460 percent from the floor.

And he finished third in the voting for G League MVP, pouring in 22.9 points, five rebounds and five assists for Long Island. (Windy City’s Carik Jones won MVP).

Now Duke Jr. fills the roster opening created by Brown’s departure.

The 7-foot-2 center had been on a second 10-day contract which ran out Thursday, and Brooklyn couldn’t sign him to a third.

They had to either ink him to a standard deal or let him go; and since he was ineligible for the playoffs anyway (as a result of being signed and waived by the Knicks after March 1), it made the call easy.

Brown, still only 23, logged just six minutes total in a pair of brief cameos.

But his presence — as well as the earlier 10-day contract to Nerlens Noel — appeared to positively motivate second-year pro Day’Ron Sharpe, a 2021 first-round pick.

Still, neither backup center is going to get used in a likely playoff series against MVP favorite Joel Embiid, who dominates even the best of veteran centers.