Actor Kelsey Grammer and actress Sanaa Lathan at the “Boss” panel. (Frederick M. Brown/GETTY IMAGES)

In the Chicago-set drama, Grammer plays Mayor Tom Kane, who is facing a fatal illness and trying to change his nature to achieve redemption. Grammer thinks it’s his “King Lear.”

“I can’t tell you how many people come up and tell me, ‘That’s the best thing you’ve ever done!’ . . . There are also people who come up to me and say, ‘When are you coming back to television?’ ” Grammer joked of the show’s challenged ratings.

Grammer says he does not know exactly what the numbers are.

Show creator Farhad Safinia, on the other hand, says: “I am completely aware what the numbers are and I’m heartbroken. . . .It deserves a larger audience.”

In the second season, which debuts Aug. 17, Kane beats back the physical symptoms of his debilitating neurological disorder with high doses of medication — but he suffers heightened psychological manifestations of the disease. Kane now has a new chief of staff, played by Sanaa Lathan, and a new adviser, played by “Glee’s” Jonathan Groff.

“ ‘Boss: the Musical’ can be seen at the Pantages Theater,” Grammer joked of Groff’s joining the cast.

Yeah, and if TV critics ever are attending a stage production starring Grammer, they’ll be sure to keep their cellphones turned on, and will feel free to answer them should they ring — after Grammer did the same to them during the “Boss” Q&A session.

As Grammer and gang lobbied for “Boss” in the Beverly Hilton ballroom filled with journalists and company, Grammer’s cellphone rang and he took the call.

It was his wife.

Can everyone keep it down? Kelsey Grammer is on the phone. (Frederick M. Brown/GETTY IMAGES)

Only at that point did some technician turn off Grammer’s microphone, so TV critics could not hear as Grammer read the phone number of his publicist, Stan Rosenfeld, to wife No. 4, Kayte.

“Kelsey Grammer is actually taking a phone call while in the middle of his #TCAs12 panel and he is not keeping it brief. Power corrupts?” a pop culture writer/deputy TV editor tweeted angrily.

“Bad manners: Grammer takes a call while in the middle of the press conference#TCAs12,” agreed a TV critic in a tweet.

“KelseyGrammer has answered his phone onstage & we are now listening to his conversation. Some find this to be charming,” added another critic’s tweet, even more peevishly.

“For the record, I would NOT take a phone call from my wife while sitting on a #TCAs12 panel,” tweeted the most miffed critic yet.

While Grammer made sure all TV critics’ eyes were on him and his phone call, “Boss’s” other cast members on stage stretched their improv muscles:

“I like your sneakers,” Sanaa Lathan, who plays Kane’s incorruptible new chief of staff, told Tip “T.I.” Harris, who plays Trey.

“They’re the Olympic Jordans,” Harris told Lathan.

Groff contributed nothing. Possibly he was still thinking about “Boss: the Musical.”

The Q&A session never seemed to regain the full attention of the critics/bloggers/tweeters after the phone call. Wrapping things up, one critic said to Grammer that he figured there would be many reports about the actor’s having taken a somewhat lengthy phone call during this Q&A session. The critic thought he should ask Grammer: “Why did you do that?”

“There are some things that are more important than others and, in my world, the well-being of my wife sits on top of the charts,” Grammer said.