The NBA announced on Wednesday that 66 players are expected to attend the 2019 NBA Draft Combine May 14-19 in Chicago. The event is the first step in the draft process for many prospects.

Of those 66 players announced, some of the top draft picks, like Zion Williamson, Ja Morant and R.J. Barrett, are among those expected to be in attendance for the event.

While some of the biggest names in the draft class will take part in the event, there were a few notable players that were not included on the list. Perhaps the biggest name not listed: Washington guard Matisse Thybulle.

Thybulle is currently projected by ESPN to be selected by the Philadelphia 76ers with the 24th overall pick. While some prospects have skipped portions of the event, it is rather rare that a player skips it altogether.

There are a number of factors that often play into a prospect declining an invitation. Injuries sometimes prevent players from going while other prospects, with feedback from their representation, skip it to hide potential flaws from teams.

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One of the biggest reasons for a prospect to skip the event is if they receive a draft promise from a certain team. Last year, former Boise State forward Chandler Hutchison pulled out of the Combine at the last minute because he received a promise from the Chicago Bulls with the 22nd overall pick.

Teams give promises to prospects to ensure they do not work out with other clubs. The speculation now is that Thybulle may have received a promise from the Oklahoma City Thunder with the 21st overall selection.

If Thybulle has a promise (reason for not attending the combine) 21 to OKC seems a little high relative to popular consensus but he's about as Presti as it gets — Cole Zwicker (@colezwicker) May 8, 2019

The 6-foot-6 forward averaged 9.1 points, 3.5 steals, 3.1 rebounds and 2.2 blocks in 36 games last season at Washington. He shot 41.5 percent from the field and 30.5 percent from three-point range.

But Thybulle separates himself on the defensive end.

The senior was named the 2019 Naismith Defensive Player of the Year and is widely considered the best defender in the draft. His defensive instincts have proven to be off of the charts given his steals and blocks per game.

Thybulle led the Pac-12 in steals last season and passed Gary Payton to become the conference’s all-time steal leader. He is the only player since the 1992-93 season to record at least 100 steals and 60 blocks in a single season.

Given Thunder general manager Sam Presti’s love for defensive-minded players, it is easy to see the possible connection to Thybulle.

For those who don't know, both Westbrook and Roberson were Pac 12 (well, 10 for Westbrook) DPOY players. Yeah, I'm feeling that Thybulle promise possibility. https://t.co/43nDLKl6NZ — David Brandon (@birdrightsnba) May 8, 2019

While many are starting to believe a promise has been made to Thybulle, it has not yet been reported that such a deal is in place by the Thunder, or any other team for that matter. So, the idea is purely speculation at this point but the evidence certainly suggests that the Thunder could have interest in him.

Thybulle has been projected by most to be taken in the early 20s so the Thunder potentially selecting him at No. 21 wouldn’t appear to be a reach by any means. While his offensive game is still a work in progress, he projects to check a lot of boxes defensively.

We’ll see if anything comes of this in the coming weeks.