According to RFR, Jason Reiner will replace Joel Edmonds as Biffle's spotter this weekend at Michigan International Speedway for Sunday's Pure Michigan 400 (2:30 p.m. ET, NBCSN, MRN, SiriusXM). Reiner has spotted for Chase Elliott.
"It is not one of the changes I was looking for, but it was time to head down a different path for the company," Biffle said.
"Like I said, it was not preferable to start with a new spotter, especially with Bristol next weekend and four races before the Chase, but it is a business and we will work for it the best we can to get up to speed with listening to a new guy up top."
Biffle leads active drivers with four Cup victories at Michigan, with his most recent win coming in 2013. He has 15 top-10 finishes in 25 Cup races at the track.
Biffle is 80 points behind Clint Bowyer for the 16th and final Chase slot. He finished in the top five two races ago at Pocono Raceway, one of two top-five finishes this season (the other coming at Charlotte).
"Greg has won two of the most significant races we've won here -- the 100th anniversary for Ford Motor Company and the 1,000th win for Ford," team owner Jack Roush said about Biffle's success at Michigan. "We are looking forward to the new setup here with the aero and we look forward to seeing what we can do."