BOSTON — Knuckleball pitchers are a rare breed in baseball, and they are just as rarely understood. Many people don’t realize that, despite slow-tossing the ball toward home plate, knuckleballers suffer from the same ailments as any other pitcher.

Kevin Cash has caught knuckleballer Tim Wakefield all season long, and he knows that when Wakefield was ailing with stiffness in his throwing shoulder, it hurt his effectiveness, regardless of how hard he throws.

“It doesn’t matter if you’re throwing 95 [mph] or 65 — if your arm is aching when you’re throwing, it’s going to affect you. It affects the finish on his knuckleball. When his arm feels good, he has that finish. When his arm is tired, or grabbing or whatever it is, he doesn’t get that finish,” Cash said.

Cash caught Wakefield at the end of the season, after the pitcher came off the disabled list, and the catcher noticed immediately that Wakefield’s arm seemed fresher. He expects to see that fresh arm out there tonight.

“I think he’s going to feel good. He’ll be excited, and even if he doesn’t [feel good], hopefully some adrenaline will kick in,” Cash said.

dbarbari@projo.com