Tyler Reddick is competing in the Southern 500 at Darlington while dealing with an illness, and Martin Truex Jr. could take over if things get really bad. The broadcast team on NBC Sports (per Stephen Stumpf of Frontstretch) said Reddick’s team hasn’t reached out to Truex yet. He would be a “last resort” and even if that happens, there would be issues with adjusting the seat. Truex wrecked his car two laps into the Southern 500, so his day is done. But with him being a Toyota teammate, he could replace Reddick who already clinched a playoff spot. Truex is in a good position to reach the postse…