Gamboa, 29, was 4-6 with a 3.64 ERA in 16 starts at Double-A Bowie and 2-5 with a 6.23 ERA in nine starts at Triple-A Norfolk. He's 37-34 with a 3.37 ERA in six minor league seasons in the Orioles system.
The highlight for Gamboa last year was throwing a seven-inning no-hitter for Bowie on June 30 against Harrisburg.
The Orioles placed Gamboa on the 40-man roster on Nov. 20 before non-tendering him on Dec. 3. They basically had an agreement in place to re-sign him at a later date.
Gamboa pitched in Mexico this winter, going 3-4 with a 2.64 ERA in 11 starts.
Clark, 30, made his major league debut with the Orioles on May 1 in Seattle and allowed three runs and three hits in 1 2/3 innings. The Orioles designated him for assignment three days later to make room for Freddy Garcia on the 25- and 40-man rosters.
Once Clark cleared waivers, the Orioles suggested that he learn how to throw a knuckleball.
Clark (UMBC) pitched at four levels of the farm system last year, going 3-15 with a 7.84 ERA in 25 games (24 starts). He was 1-7 with a 9.74 ERA in 10 starts at Single-A Frederick while going through the conversion to knuckleball pitcher.
"It was a lot harder than I thought it was going to be," Clark told MASNsports.com's Steve Melewski in October. "I knew it was a challenge, but didn't know how hard until I was going through it. It took me a while to get comfortable. As I got more comfortable, especially that last month in Frederick, I really started to figure out some things. I had a feel for it.
"I was able to pitch with it. A lot of times in games (earlier), I had no idea whether it would be a ball or strike and I had to really mesh my other stuff together. I had a lot of trouble combining the two - my conventional pitches and my knuckleball."
Hall of Fame knuckleballer Phil Niekro has been working with Gamboa and Clark and is expected to do so again in 2014.