Tim Burchett said he isn't surprised U.S. Rep. Jimmy Duncan won't endorse his candidacy to replace the longtime congressman.

Burchett, Knox County's two-term mayor and a former state lawmaker, said in an appearance that airs Sunday on WBIR's "Inside Tennessee" that he's always considered himself the underdog, not someone who runs with "the big boys."

"Sure, I would have enjoyed having (Duncan's endorsement)," he said on the public affairs program. "I would enjoy having a lot of people's endorsements. But I've never curried the favor of the in-crowd."

The Republican Duncan announced earlier this month he would not seek re-election next year after nearly 30 years in the U.S. House. Two days later he told 10News he had no intention of endorsing Burchett, a Republican, for the position and that he expected other good candidates to enter the race.

It's long been expected that Burchett would seek Duncan's seat. Duncan first was elected in 1988 following the death of his father, John Duncan Sr., who held the seat more than 20 years.

It's going to be a crowded field next year in the local GOP primary.

Besides Burchett, state Rep. Jimmy Matlock of Lenoir City and Brad Fullington of Knoxville and Ken Gross of Knoxville have submitted plans to seek the 2nd District seat as Republicans.

That means there'll be at least four people running in the August 2018 GOP.

Also running is Democrat Joshua Williams, and it's possible more local Democrats will file to represent the seven-county district.

Channel 10's "Inside Tennessee" will air 9:30 a.m. Sunday.