Sports Illustrated published excerpts from the book on Wednesday.
"Everyone I knew was unimpressed with Valentine, the new manager of the Red Sox," Ortiz said in the book, written along with Michael Holley. "He was hired in late November 2011, and the negative reaction from my baseball friends was instant. There were the sarcastic "good luck" messages. There were ominous warnings to get ready. Some even suggested that, at 36 years old, I probably wanted to retire rather than play for someone like him."
Ortiz explained that he wanted to see for himself how bad Valentine actually was. He said Valentine managed in a "bubble."
"There had been a lot of conversations about our team the year before and how our lack of accountability led to our September collapse," Ortiz said. "Maybe Bobby was told to come in and boss around full-grown men. Maybe the Red Sox wanted to hire a daddy, not a manager."
Ortiz, who retired last year, explained that team leaders even approached Valentine about his perception among the players, but he didn't listen.
Valentine responded to the comments Thursday on CBS Radio. He said he hopes he can help Ortiz sell books.
"Well, I wish he told me three weeks into the season instead of hugging me all the time when he saw me! Yeah, that was a weird situation," Valentine said.
"I hope he sells a lot of books. I hope I help him sell some," Valentine said.
Valentine is now the athletic director at Sacred Heart University. His 2012 tenure with the Red Sox resulted in a 69-93 record and led to his firing. He hasn't managed in Major League Baseball since that season.
The Red Sox won the World Series a season later under first-year manager John Farrell.
Ortiz, 41, played 14 of his 20 pro seasons for the Red Sox. He was a 10-time All-Star, seven-time Silver Slugger recipient and a three-time World Series champion. "Big Papi" won rings with the Red Sox in 2004, 2007 and in 2013. He retired with 541 home runs and a .286 career batting average.
Papi: My Story is available on Tuesday.