Johnson underwent surgery shortly after the end of the 2014 season to remove a large bone spur behind his right shoulder. He registered a 6.23 ERA in 47 2/3 innings at three different levels in the minors, with most of his action coming with Triple-A Norfolk. He's expected to be ready for spring training.
The team has also announced that infielder Gregorio Petit has accepted an assignment to Fresno. He and Downs are set to join the squad in spring training.
Downs also received a non-roster invite to MLB camp.
Gomes split last season between Tampa Bay and Triple-A Durham. He finished the year with a 2-2 mark and 3.71 ERA in 29 relief appearances.