That depth will now be tested after Wednesday's announcement that Yasmani Grandal will miss the first 50 games of the season without pay after testing positive for testosterone.
Grandal, who turned 24 on Thursday, was projected as the Padres' starting catcher after showing well in his first Major League stint, when he hit .297 with eight home runs and 36 RBIs in 60 games.
"Grandal got the opportunity and ran with it," Byrnes said in September.
Barring any additions to the roster -- and the Grandal suspension won't likely mean the team will add a catcher this winter -- the team will go into the 2013 season with John Baker and Nick Hundley as its catchers.
Before the Grandal suspension, Baker might have been a non-tender candidate.
"We still have Hundley and Baker. We have decent coverage there," Byrnes said Wednesday. "Hundley had knee surgery at the end of the year. He's feeling good. Hopefully he'll be full go in Spring Training."
Hundley, who signed a three-year, $9 million deal in March, was the team's Opening Day catcher. But he struggled at the plate, hitting .166 in 55 games before being sent to Triple-A Tucson. In August, Hundley had season-ending surgery to repair a torn right meniscus.
Baker, who was acquired last winter from the Marlins, hit .238 in 63 games and earned rave reviews for his work with the pitching staff.
The Padres only have two catchers -- Baker and Hundley -- on their 40-man roster. They lost Ali Solis to the Pirates on a waiver claim last month, though he didn't figure in their future plans.
But the starting job for 2013 and beyond was clearly going to fall on Grandal's shoulders. Now, he won't be eligible to play until May 28 when the team is in Seattle for an Interleague series.
So what will now become of Grandal?
He will be eligible to participate in Spring Training and in exhibition games. After the Padres break camp at the end of March, Grandal will remain in Arizona to take part in the team's extended spring training program. He can work out with the Padres and take batting practice with the team as long as it's before the gates of the ballpark are open.
Grandal, who is on the restricted list and will not count toward the 40-man roster, will be eligible for a Minor League assignment that cannot exceed 10 days. That would likely occur toward the end of his suspension, a precursor to being reinstated to the Major League roster.