Tommy Kahnle was activated from the disabled list Friday after missing over a month with shoulder tendinitis. Lefty Ryan Bollinger was optioned to Double-A Trenton on Thursday to open a roster spot.

Boone said he was pleased to have Kahnle’s “dynamic arm” back in the bullpen.

“The deeper we are down there with really strong options, the better we’re going to be,’’ Boone said. “We feel like Tommy, when he’s right, is one of those impact options for us.”

Kahnle’s return should take some pressure off the rest of the pen, including David Robertson, who has struggled of late.

Heading into Friday’s game, Robertson had given up six runs in his past four outings, covering 3 ²/₃ innings. The right-hander also had walked six and struck out only four.

Boone said he didn’t believe there were any “red flags” involving Robertson.

“I think his command is just off,’’ Boone said. “It’s a little bump in the road for him. I’m quite confident he’ll power right through.”