Harrison, 27, was 18-11 with a 3.29 ERA in 32 starts last season (213 1/3 innings). He is arbitration-eligible for two more years and made $2.95 million last year.
"I like it here and want to be with this team," Harrison said. "We'll see how it goes. We're still talking."
MLB.com first reported that the club was talking with Harrison.