Concerned About Health Issues In 'Last Match'

Ric Flair is one limousine ridin', jet flyin' tough son of a gun ... but even he admits that he's worried about his health failing him in the final wrestling match of his historic career later this summer.

The WWE legend was speaking to reporters in Nashville on Thursday while promoting his much-anticipated "Last Match" bout ... and he revealed he does have some concerns about previous health issues popping up during the tilt.

Specifically, the 73-year-old said he's worried about his pacemaker ... as well as some inner ear problems he's had in the past.

Flair also hinted blood thinners could have an impact on his body as well.

The Hall of Famer, though, did say he's not horribly concerned about…