4. J.A. Happ
Happ made his big league debut for the Philadelphia Phillies in 2007 and struggled to find himself in the majors. However, it appears that Happ may have finally settled in, having his best season to date in 2015. He set a career high in fWAR (3.3) and had his second-best ERA (3.61) and K/9 (7.90).
Happ relies on inducing ground balls and successfully did this in 2015 with a 41.6 percent groundball rate — the second lowest of his career. He could provide a team with an above-average number-three or -four starter at a reasonable price.
Look for the New York Yankees, St. Louis Cardinals, and San Francisco Giants, among others, to take a look at Happ.
Note: Happ could not receive a qualifying offer because he was traded midseason, giving his market a little boost.