James Small knew what was happening when he saw Christopher Bell slow on pit road at Las Vegas

CONCORD, N.C. — While crew chief Adam Stevens told Christopher Bell to find a teammate's pit stall to tighten a loose wheel on the No. 20 car during last weekend's race at Las Vegas, how much warning did crew chief James Small have that Bell would stop in his team's pit stall?

None.

No warning was needed.

"If you're down on that end of pit road (close to pit exit), we just, for years, we've had an agreement that if somebody rolls up to your pit box, you know what you need to do," Small told NBC Sports on Tuesday after the first of a two-day tire test at Charlotte Motor Speedway.

Small, crew chief for Chase Briscoe, saw Bell slow on pit road and knew Bell's plan. Bell avoided traffic on pit road and entered Briscoe's pit stall cleanly.

"I could see Bell trying to get to our box and I'm like he must have a loose wheel," Small said. "He came in and he was pointing and I got on our in-car radio and started yelling, 'Left front! Left front!'"

Briscoe, who was on the track under the caution, said he was startled when he heard Small yelling on the radio about the left front tire and thought that was something wrong with his car. Once Bell was away from Briscoe's pit stall, Briscoe was told what happened.

It was ingenious, really — and well thought out.

Small said that Joe Gibbs Racing's teams have talked about having a teammate pull into another's pit to have a wheel tightened "for many years now and that's just the first time it's happened."

Had Bell gone back on track and the loose left front tire come off, he would have been penalized two laps and had two pit crew members suspended for the next two weeks — infractions Briscoe's team and Kyle Busch's team had at Las Vegas.

But by having Briscoe's team tighten the loose wheel, Bell was only penalized for pitting outside his stall. That sent him to the back of the field for the restart.

"When I saw it, my initial reaction was that was really smart to do what they did," Ryan Blaney told NBC Sports. "Honestly, we've had discussions about it the last couple of years."

As Bell headed down pit road on the outside lane, he had William Byron next to him on the inside lane, at least briefly.

"It was kind of weird because I was like 'All right, I'll feel like I'm going to be racing him off pit road and then he started slowing down," Byron said Tuesday at the tire test. "When we talked about it under caution about what happened I was like that's pretty heads up for them to anticipate that and obviously they've talked about that in the past."