Eventually, the Knicks did it.

Eventually, they actually made and kept their picks.

They began the second round of the NBA draft Wednesday like they left off in the first round Tuesday — by trading. They started the night with the Nos. 31, 47 and 55 picks. But they sent Nos. 31 and 55 to the Rockets in exchange for Nos. 39 and 53 along with a future Kings second-rounder.

And then at No. 39, they drafted German youngster Jack Kayil. A 20-year-old, 6-foot-5 guard, Kayil played professionally for Alba Berlin in the German Bundesliga. He averaged 12.3 points and 3.5 assists per game on 40 percent shooting from the field and 34 percent shooting from 3-point range last season.

Kayil won the Bundesliga’s Best Young Player award and committed to Gonzaga before opting to stay in the draft.

He plans to join the Knicks, not go back to Germany as a stash option.

“Not really,” Kayil said. “My plans are to stay here and get into the organization and keep going with them.”

He thinks his experience overseas has helped his development.

“I think I already saw,” Kayil said, “for a young guy, a lot of places and different things, different plays and different systems and I think it can help me in the future.”

Then at No. 47, they selected Tyler Nickel, a big-time shooter out of Vanderbilt. A 6-foot-7 forward, he averaged 13.5 points and shot 40 percent from 3-point range as a senior last year.

Finally, at No. 53, the Knicks picked shot-blocking center Ugonna Onyenso out of Virginia — who could have been potential insurance with Mitchell Robinson’s future uncertain — but quickly sent him to the Pistons for cash.

It is clear the Knicks, who have limited space to stay under the second apron, which owner James Dolan said they intend to do, did not want to pick in the first round and have to pay the salary that comes with the guaranteed contracts first-rounders get. And even though second-rounders are usually less expensive and don’t automatically get guaranteed contracts, the Knicks opted against making a selection at the beginning of the round, which would have likely commanded a higher salary than they could afford to give.

But, eight and 16 picks later, Kayil and Nickel should command less money — at or closer to the rookie minimum — than anyone they would have selected at No. 31. They could even potentially be signed to two-way deals.

On Tuesday, the Knicks originally had the No. 24 pick but, after a four-team deal, moved out of the first round and left with five additional second-round picks, the draft rights to three international players who are unlikely to ever sniff the NBA, plus cash.

So, in total between the two rounds, the Knicks sent away three picks, kept two picks that should be economically friendly and added a handful of second-rounders for the future.

Everything right now revolves around the second apron. The Knicks acted accordingly.