Seattle manager Don Wakamatsu said before Sunday's game that scans on Kelley's right elbow have been inconclusive as to what is causing Kelley's discomfort and surgery is likely the option.
Kelley says he is having some tests on Monday that will be the final determination if he will go ahead with having surgery.
Kelley was placed on the disabled list June 25 with inflammation in his right elbow. He was scratched from a rehab appearance at Class-A Everett last Thursday. He is 3-1 with a 3.96 ERA in 22 appearances this year.