Only two of the Tigers’ top 10 picks in the 2017 MLB Draft remain unsigned.

One is their first-rounder, right-hander Alex Faedo, who is pitching for Florida in the College World Series and can’t sign until that run is over.

The other is fifth-rounder Sam McMillan, a high-school catcher from Florida who could prove to be a tough sign.

He is committed to the Florida Gators.

The Tigers seemed to acknowledge the challenge in signing prep players, especially outside of the first few rounds, where the money is really good. Slot value for McMillan’s spot, at No. 155 overall, is $313,900.

“Everybody’s different. You know when you draft them later, obviously it gets tougher,” said Scott Pleis, the Tigers’ director of amateur scouting. “We know these kids pretty well, so there’s some we think might be signable. Some are tough.

“At that point, it’s worth the risk to try. We put enough work in them and we like them, it’s worth drafting them and going through the process.”

Detroit drafted just two high-school players through 30 rounds, and then six in the last 10 rounds — including three star players from Michigan, all of whom are expected to go unsigned and head to college.

McMillan is a 6-foot-1, 190-pound catcher from Suwannee High School in Live Oak, Fla.

He’s a line-drive hitter with a strong arm, though he suffered some soreness in his arm early in his senior season, which scared off some major-league teams.

The Tigers circled back later, and the arm strength had returned, convincing them he was worth a shot.

He was the second catcher they took through five rounds, the other Washington’s Joey Morgan in the third round.

“We saw what we needed to see,” Pleis said of McMillan. “A great kid. Maybe we liked him a little more than what the other guys saw.”

The last time the Tigers failed to sign a pick from the top 10 rounds was 2015, when seventh-rounder Nicholas Shumpert, a high-school infielder, decided to place JUCO ball. He was drafted the following year, 21 rounds later, by the Atlanta Braves and signed that time.

Of the Tigers’ top 10 picks in 2017, at least four signed for less than the picks’ slot value, and a couple for significantly less than slot. That could free up money to sign Faedo and maybe sweeten the pot for McMillan.

Each team has a set MLB Draft bonus pool, and the Tigers’ is a little more than $6 million.

The Tigers announced Tuesday that they’ve signed 17 of their 40 picks, including Dane Myers, a two-way star at Rice and a right-hander. That was the lone previously unreported top-10 signing by the Tigers.

Among the other players signed include 12th-rounder Will Vest (RHP, Stephen F. Austin) and 22nd-rounder Colby Bortles (3B/Mississippi), the brother of Jacksonville Jaguars quarterback Blake Bortles.