The only difference, as far as I can see, between the backup catcher in baseball and the backup quarterback in football is that no one clamors for the former to play. Other than that, you can barely slide a credit card between the two positions, in terms of what they mean to their respective teams.

Both are non-starters for a reason.

Yet in the NFL, there is a mystique about the backup quarterback. He’s not the starter, but as soon as the real starter goes a little sideways, everyone from the crank yankers calling in to sports talk radio to your Uncle Gus can’t wait to see the No. 2 QB jogging onto the field.

Not so with the backup catcher.

The backup catcher is someone who can’t hit, who can’t run and whose only seemingly redeemable quality is that he’s “a good clubhouse guy.”

At least the backup quarterback has been known to save the day on occasion, with a heart-stopping drive at the end of a game or a surprising starting performance that makes him look, for 60 glorious minutes, like the second coming of Johnny Unitas.

The backup catcher is a guy who plays only because the starter can’t possibly catch all 162 games.

The Tigers tried to have Alex Avila catch that many games last year, or so it seemed. He was given less time off than an accountant during tax season.

There was a pseudo rotation between Avila and the newly-signed Victor Martinez for a time, but Victor’s knees couldn’t take the punishment and he was relegated solely to designated hitter duties.

That left Avila, with token appearances by utility man Don Kelly and a couple of dudes from the stands, if memory serves.

The Tigers have provided Avila with some relief, however, for 2012 with the signing of—drum roll, please—our old friend Gerald Laird.

He’s baaack!

For what the backup catcher normally provides offensively, Laird fits the bill. He also fit the bill in 2009 and 2010, during his first tour of duty with the Tigers. Trouble was, he was the starter—and still hitting like a backup.

I don’t have the time or the energy to do the research, but if you were to tell me that the mean batting average for backup catchers last year—or any year, for that matter—was around .200, I wouldn’t bat an eye (no pun intended).

That’s what backup catchers do, you know. They hit around .200, play once a week, maybe twice, and the hope is that they just don’t screw anything up.

They’re like substitute teachers, in a way.

Laird had the last laugh, though. Tigers fans weren’t exactly enamored with him after his less-than-spectacular hitting prowess (he hit a composite .218 in his two Detroit seasons), and were happy when he wasn’t asked back for 2011.

That’s OK—for Laird, who hooked up with the St. Louis Cardinals last December, got all of 95 at-bats in 2011, hit a robust .232 and (here’s the punch line) won a World Series with the Cards.

All the great catchers in baseball history had their caddies, which are what the backups are, essentially.

The Yankees’ Yogi Berra had his Charlie Silvera. The Reds’ Johnny Bench had his Bill Plummer. The Tigers’ Bill Freehan had his Jim Price.

Silvera, Plummer and Price were your typical backup backstops. That is, they couldn’t hit their way out of a paper bag. None was a threat to unseat the starter ahead of them.

Tigers fans might have rolled their eyes at the news of Laird’s signing last week, but he makes sense, frankly. Laird already knows the Tigers pitchers, for the most part, he has no grandiose ideas of taking young Avila’s job and he hits the requisite .200-ish.

But in fairness, the backup catcher should at least field a little, and Laird can do that. His 32-year-old arm is still strong enough to keep would-be base stealers somewhat honest.

The Tigers just need Laird to catch no more than 40 games next season, stay out of the way and don’t screw the pitchers up. It’s all any big league team asks of its No. 2 catcher.

Oh, and be a good cheerleader, that so-called “good clubhouse guy.”

When the Tigers went to the World Series in 2006, they had Vance Wilson around as Pudge Rodriguez’s caddie. If backup catchers were an organization, Wilson would have been a card-carrying member.

Actually, Vance might have been the Chairman of the Board, for he spent several seasons backing up Mike Piazza with the Mets before coming to Detroit to give Rodriguez an occasional breather. That’s playing second banana to two Hall of Famers. Not bad.

Wilson actually batted .283 in 152 at-bats with the ’06 Tigers, and he was widely recognized as one of the best backup catchers in the game—not that they give out any awards for that.

And Wilson was consistent. Before his career ended with a bad elbow injury after that 2006 season, Wilson in his final three seasons had 157, 152 and 152 at-bats from 2004-06, respectively. He was Mr. Backup—the Sultan of Squat.

Wilson was manager Jim Leyland’s attitude guy, too.

After he hurt his elbow in spring training, Wilson stayed with the team all season in 2007, rehabbing and keeping his spirits up—and those of his teammates with his practical jokes and loosey-goosey demeanor.

I saw him in the clubhouse a couple times in ’07, and on both occasions I asked him how close he was to coming back and playing.

“REAL close. REAL close,” he’d say.

Wilson never did play after 2006.

No matter. The backup catcher is the never-say-die guy on the baseball team. He’s often the least pretentious and with the smallest ego. He’s just happy to be in the big leagues.

As well he should, given his hitting skills.

Welcome back, Gerald Laird! It’s nice to have your .200 batting average, good defense and slow legs back with the Tigers.

Just don’t screw anything up.