San Francisco 49ers' Boone calls Harbaugh "insane"

SAN FRANCISCO, April 20 (UPI) -- It only took one season for Alex Boone to go from love to resentment when it comes to former San Francisco 49ers coach Jim Harbaugh.

"As a matter of fact, I know for a fact that everybody loves Harbaugh," Boone said in a radio interview last year. "He's a great guy. He's a great coach. How could you not want to win for a guy who wears cleats during a game? Come on, now. Have you ever seen that guy's energy? He's excited 24/7. You got to love to play for a guy like that. That's what football's all about."

Harbaugh, who coached the 49ers from 2011 to 2014, compiled a record of 44-19-1. Harbaugh's 49ers won the NFC championship in 2012 and won its division twice. Harbaugh's teams had a 5-3 playoff record.

Harbaugh has coached, in some capacity, at Western Kentucky, the Oakland Raiders, San Diego, Stanford, and San Francisco. Michigan hired Harbaugh, who quarterbacked the Wolverines from 1983 to 1986, in December.

"I think he just pushed guys too far," Boone told HBO's "Real Sports with Bryant Gumbel" for an episode that will air Tuesday. "He wanted too much, demanded too much, expected too much. You know, 'We gotta go out and do this. We gotta go out and do this. We gotta go out and do this.' And you'd be like, 'This guy might be clinically insane. He's crazy.'"

Boone, 27, signed a five-year, $7.450 million contract in 2011, under Harbaugh.

"He does a great job of giving you that spark, that initial boom," Boone told HBO. "But after a while, you just want to kick his ass. . . . He just keeps pushing you, and you're like, 'Dude, we got over the mountain. Stop. Let go.' He kind of wore out his welcome."