Detroit Tigers will miss Alex Avila's contributions during time on disabled list

Alex Avila will be out of action for the next several weeks with a knee injury that will probably require arthroscopic surgery. He has been the Detroit Tigers' starting catcher for the past five seasons, and was playing about 60 percent of the time behind the plate, hitting .200/.342/.317 in 74 plate appearances this season.

This injury hurts the Tigers more than some are letting on. Tigers' manager Brad Ausmus, who was a major league catcher for 18 seasons, said of Avila's injury, "It stings a lot, I would say. He's really the starting catcher, he's a left-handed bat in a right-handed lineup, and he's got a ton of experience behind the plate."

The only good news that comes out of this injury is that the club will have a better opportunity to see how James McCann performs with regular playing time. McCann, who is viewed by many as the heir to Avila's job after this season when Avila will be a free agent, will assume the starting duties in Avila's absence. McCann won the backup catching job over Bryan Holaday during spring training. Holaday, who was called up to the majors to replace Avila, was the backup for the entire 2014 season.

But Avila's loss is not good news for the team. Avila is a team leader and a contributor to the success that the team has enjoyed on the field. Anyone who thinks that Avila will not be missed is mistaken.

I always have to chuckle when I read comments criticizing a catcher based on his batting average or the number of times he strikes out at the plate. For a catcher, that is not what's important. A catcher's primary responsibility, and his value to the team, is catching. What a catcher does behind the plate is far more important to his team than what he does at the plate.

The starting catcher has to call every pitch, keeping the team's pitchers in a rhythm. He has to come prepared with a game plan to approach every opposing hitter. He also has to keep the opposing running game in check. During the course of a game, an average hitter will make 4.2 plate appearances. Defensively, a team will face 38 plate appearances. Pitchers and catchers are involved in every defensive play, and when measuring a catcher's value, that can not be cast aside.

The undying need to quantify every aspect of a player's value on the field will leave statisticians craving with pangs of hunger when it comes to measuring a catcher's defensive contribution. In particular, the value of pitch selection -- calling the game -- is practically unquantifiable. This may help to explain the Pavlovian rush to offensive metrics.

Progress has been made in measuring certain aspects of a catcher's defensive contributions. Fangraphs measures catching defense in a quantifiable way that is consistently improving as more data becomes available.

There are a number of different defensive skills that catchers need to possess, and each of them has the potential ability to impact their overall value: arm strength and accuracy, pitch blocking ability, pitch framing ability, and pitch selection.

Using Fangraphs' measure of catching defense, Avila ranked second in the major leagues in 2014. He also led the American League, throwing out 36 baserunners attempting to steal. Avila was second in caught stealing percentage, and had a league-best three passed balls among qualified catchers.

This is not to say that offense is not important. On the contrary, every batter in the lineup is important, but few catchers provide better than league average production at the plate. Only six catchers in the American League logged enough plate appearances (502) to qualify for the batting title. Among the dozen catchers with at least 350 plate appearances, Avila ranked sixth in weighted on-base average (wOBA). His on-base percentage ranked fourth in the league thanks to a team high 13.3 percent walk rate.

The league average on-base percentage for hitters in 2014 was .316. For catchers, it was .286. Avila's on-base percentage was .327. In 2015, being used in a platoon where he faced fewer left-handed pitchers, his on-base percentage is .342. League average on-base-plus-slugging-percentage (OPS) for catchers was .642 last season. Avila's OPS was .686.  While his batting average won't impress anyone, he managed to hit .215/.340/.380 against right-handed pitchers.

Without Avila in the lineup, the Tigers have just three left-handed hitters on the roster. The only full-time starting player among them is Victor Martinez, a switch hitter who is struggling mightily from the left side of the plate. The others are Andrew Romine and Anthony Gose.

There is reason to believe that McCann will do a capable job as a starting catcher, but he will now be challenged by a steady diet of right-handed pitching, which is something that he has not yet had to face at the major league level. McCann's defense has also been impressive so far, and his learning curve will be accelerated dramatically.

Bryan Holaday has been recalled to resume his job as the backup catcher. He has a year of major league experience in that role, but he hit just .231/.266/.276 for an OPS of just .542. That is among the lowest in the league, and he was facing mainly left-handed pitchers. McCann is a better catcher, both offensively and defensively, and so is Alex Avila.