Taken aback by speculation that his crew chief change was made largely because of the No. 99 team's disappointing performance this season, Carl Edwards spent a good portion of a 20-minute interview session explaining that former crew chief Bob Osborne really is dealing with significant health issues.

Then Edwards was interrupted by some good-natured -- but still fairly sharp -- heckling from fellow driver Clint Bowyer, who was sitting nearby.

''Hey, Carl! How many different ways can you explain how you fired somebody?'' Bowyer yelled.

A day before his first race with new crew chief Chad Norris, Edwards went out of his way to say that team owner Jack Roush made the change last week because of Osborne's ongoing health issues -- and not because the team goes into Sunday's Brickyard 400 ranked 11th in the Sprint Cup points standings.

''I can't overstate enough that Bob is a very, very dedicated guy to our sport and he is going through something right now that would be tough for anyone,'' Edwards said. ''And for him to have done what he has done at this level and to have kept it quiet, he is just a tough, tough man. He is a good friend of mine, so I am really thinking a lot of him.''

Osborne remains with the team in a management role. But Edwards said Osborne could return as his crew chief once his health issues, which the team has not disclosed, are resolved.

''What we are trying to do right now is make the team better and fix any issues we might have, which we don't even know exactly what the issues are,'' Edwards said. ''If we don't do any better here and Bob is up to it, we will probably put Bob right back in as soon as he is able. If this goes well and Bob is doing well in his new role and that is the best thing for him and Chad is doing great, then we will move forward with that. Nothing is in stone right now. It could be a whole difference scenario next week and we all know that.