These aren’t heady days for the Mets, but for the club’s director of player relations, Donovan Mitchell, they are exciting, nerve-wracking times.

Donovan Mitchell Jr., his son, has risen on the Knicks’ radar and is being considered for the eighth pick in the draft. According to sources, Mitchell, a Louisville combo guard, has a workout planned with the Knicks in Tarrytown this week.

Knicks president Phil Jackson flew last weekend to Los Angeles for Creative Artists Agency’s pro day to watch Mitchell, among others, work out. Kentucky point guard De’Aaron Fox also was in attendance, but he’s not expected to last beyond the fifth pick. Until the NBA Draft Combine last month, Mitchell wasn’t firmly in the conversation as a late lottery selection.

Although he raised his son in Elmsford, Westchester County, the elder Mitchell said he doesn’t care if his son winds up with the Knicks. His rise to a potential late lottery pick is stunning in itself.

The senior Mitchell, an infielder/outfielder, spent seven seasons toiling in the minor leagues for the Astros organization, never getting a cup of coffee in the big leagues other than during spring training. From 1999 to 2010, Mitchell served as a minor-league coach with the Mets, spending time with Triple-A Norfolk.

“Playing in the NBA is good enough for me,’’ Mitchell Sr. told The Post. “We’ve all been excited, amped up and a little nervous. We’re hoping the best is yet to come for him.

“It’s amazing to see. This is what he’s wanted since a little kid — an opportunity to play at the highest level. He deserves it. Works hard. Sacrificed a lot. He fell in love with basketball like I fell in love with baseball.’’

The younger Mitchell, 20, was a standout pitcher, but at age 13, he decided to focus on basketball full-time. He played with two AAU programs in New York City — the Riverside Hawks and The City. He doesn’t get referenced as a New York product, however, because he did almost all of his schooling at Connecticut and New Hampshire prep schools.

“Donovan’s a workaholic,’’ said Mitchell Sr., who played high school basketball at Alexander Hamilton. “When he spends time in the gym and puts his mind to what he wants accomplished, he gets it done.’’

Louisville coach Rick Pitino told The Post recently he never had a player improve his jump shot from one season to the next — aside from Billy Donovan — as much as Mitchell did.

Pitino has an affinity for New York guards. Mitchell turned down Villanova, Boston College, Florida State and Providence. His father said he wanted to play in the nation’s toughest conference — the ACC — and Pitino had a spot for him to start immediately.

“[Pitino] gave him opportunities — some of the things we don’t see in those private times in the gym,’’ Mitchell Sr. said. “Pitino and that staff got him to hone his skills, get himself to another level.’’

The 6-foot-3, 200-pound Mitchell, who played more shooting guard than point, averaged 15.6 points, shooting 35 percent from 3, with 2.7 assists and 4.9 rebounds. Pitino said Mitchell was one of the best rebounding guards he’s ever had — his wingspan measuring an impressive 6-foot-10.

“He has a good body and is a very good athlete, especially vertically — very explosive,’’ an NBA scout said. “His perimeter shot is a little streaky, but he can make the 3. His athleticism helps him finish at the rim. He has some good upside.’’

Many NBA scouts believe the eighth pick is too high for Mitchell, but Jackson said he’s trying to find team players and seamless triangle fits.

“I like best how humble he is, and he puts his team and teammates first,’’ the elder Mitchell said. “I’ve always been impressed by him being able to be there for his teammates as well as his coaches, whether he’s playing well or not. He’s a kid that keeps his head on straight and he’s very mature for his age. If he needs any advice, I’m always there for him.’’