"We were thinking about him in the third," Stan Meek, the Marlins' vice president of scouting, said. "I don't know. Just something told us he might last a little bit, so we decided to just hold on and see if it would work.
"He really was the guy we wanted, but we did take a little bit of a chance. I felt like [Wallach] falling into the fifth round ... was a very good pick for us."
The Marlins addressed the backstop position by drafting Wallach with the 152nd overall pick of the 2013 First-Year Player Draft during the fifth round on Friday.
"He's a big, durable catcher," Meek said. "I like guys who are big, strong, physical, durable guys behind the plate. … This guy's a guy who can really handle a Major League season."
Wallach enjoyed his best season for the Titans as a junior, helping Fullerton reach its first NCAA Super Regional since 2010.
He earned a spot on the 2013 Big West Conference Second Team with a batting average of .303 and a .393 on-base percentage. He led the Titans with 13 doubles this season and threw out seven runners on 17 steal attempts.
"He's always been a tough kid over there," Meek said. "He's always kind of led that team defensively, so we just liked ... everything about him with the mentality that he brings to the ballpark."
Wallach is a great fastball hitter who has a little more trouble hitting the curve and tends to swing around outside pitches. His bat speed and leverage indicate that he projects as an average power-pull hitter.
He has the proper throwing mechanics behind the plate and average arm strength for his position. His throws are typically on target when his body is under control, and he likes to get dirty behind the plate and on offense, as well. He is likely a backup catcher in the professional ranks.
The Marlins' top catching prospect is J.T. Realmuto, a converted high school shortstop playing for Double-A Jacksonville.
In the Majors, Miami is employing three catchers, with 23-year-old Rob Brantly in the starting role. Backup backstop Jeff Mathis is 30.
Wallach is the son of former Major Leaguer Tim Wallach, who serves as the Dodgers' third-base coach.
"Obviously, the bloodline is great," Meek said. "Any time, I think, you find the son of big leaguers, the percentage of those guys that play in the big leagues is pretty high -- real high -- compared to the guys whose parents or dad did not play in the big leagues."