Play video content Exclusive APRIL 2020 TMZSports.com

Kendall Jenner has a special quarantine pal -- NBA superstar Devin Booker -- and they just social distanced in the back of his Maybach together for a quick road trip to Sedona!

TMZ Sports has footage of the two during a quick bathroom break at a rest stop near the Arizona city ... and it's not like they were trying to keep a low profile.

As you can see in the clip, the two rolled up in Devin's super-fancy Mercedes-Benz Maybach (they usually cost around $200k). Plus, he's 6'5" and plays for the Phoenix Suns. And, she's 5'10" and one of the most famous people in the world!

Witnesses tell us they certainly LOOKED like a couple during the stop, but sources close to Devin and Kendall insist they're just friends.

One source puts it this way ... "Kendall and friends have a small social circle amongst the group, who have been following the same social distancing and physical distancing guidelines. Devin is a friend and is part of the small group."

"They took a road trip for some much-needed air" -- but we're told they made a concentrated effort to minimize interactions with other people.

24-year-old Kendall and 23-year-old Devin have been friends for years. They’ve been running in the same social circles since at least 2018.

Booker is one of the top young players in the NBA -- he's currently in the middle of a 5-year $158 million contract with the Suns.