It’s a good thing Mike Napoli and Jeff Mathis have a highly evolved relationship – and matching senses of humor, also fully developed.

They share and share alike, the way best friends are supposed to act.

The Angels co-catchers are fully aware of the friction generated by the fact that only one of them can play at a time, given that the designated-hitter role belongs to Vladimir Guerrero.

Most of the anger and resentment from fans come when Napoli and his booming bat are on the bench alongside manager Mike Scioscia, who values Mathis’ athleticism and game-calling ability more highly than fans fixated on raw numbers.

For the record, the Angels are 38-26 when Napoli catches, 36-21 when Mathis calls the shots. The club is 11-5 when Napoli is the DH.

Before Sunday’s series finale at Rogers Centre, Napoli getting the call against southpaw Ricky Romero, the two catchers were having some laughs when the subject of the perceived competition between the two was dropped in their laps by your faithful correspondent.

“I know a lot of people want Mike in there,” Mathis said. “I understand why.”

Fans – not just chicks – dig the long ball. Napoli, after a three-run ninth-inning bomb on Friday night, has produced 17 homers and 48 RBIs in 306 at-bats, about a half-season worth. Mathis has five homers and 26 RBIs in 179 at-bats.

No catcher in history has produced homers per at-bat at a greater rate than Napoli.

Napoli is hitting .297, Mathis .212 – despite an August surge during which he has hit .294. All five of his homers have come in his past 29 games.

“If you want fans to like you more,” Napoli said in that familiar banter that goes on between the two best buddies, “hit better than .212.”

“I’m trying, I’m trying,” Mathis replied, grinning.

The most important aspect of their relationship is the mutual respect. They’re constantly sharing information, offering advice and encouragement, a team within a team.

Napoli admires Mathis’ remarkable athleticism and defensive skills and is keenly aware that the staff ERA shrinks by almost a run when his buddy dons the catching gear.

Mathis is in awe of Napoli’s hitting skills and plate discipline, which are on a level with most of the game’s premier sluggers.

They’ve been roommates for years now. Fans readily take sides, most of them drawn to Napoli’s loud bat, but nothing will drive these two guys apart.

The Angels are lucky to have two premium receivers — even if fans don’t realize it. A third, Bobby Wilson, has Major League skills at Triple-A Salt Lake, and Hank Conger and others are making progress throughout the organization.

Scioscia always says you can’t have enough good pitching, but he obviously feels the same way about guys who ply the trade he handled so well for so long.