But way before covering the Yankees and Red Sox, it was the Central York Panthers and Dallastown Wildcats that Rosenthal was reporting on.
Rosenthal -- Fox's lead field reporter for the American League Championship Series and the World Series and the senior baseball writer for FoxSports.com -- started his career as a journalist 25 years ago in York.
It seems like an odd starting point. After all, what would bring a Queens, N.Y., boy and standout reporter from the University of Pennsylvania to York County?
Rosenthal almost laughs. He mailed about 75 sports editors his resume back in 1984. And he earned exactly one job offer -- from the York Daily Record. He accepted it.
"It wasn't like it is now, where there are no jobs in newspapers," Rosenthal said. "But it was difficult to break in."
Don't be shocked, but Rosenthal already had a key contact. A college buddy, John Dellapina, had landed a job in York the year before. Dellapina mentioned the opening, and Rosenthal did the rest.
"Kenny, even from the outset when I first met him, was one of the best writers I knew," said Dellapina, who worked with Rosenthal at The Daily Pennsylvanian, Penn's student newspaper. "He was either a sophomore or a freshman, but he was already a star.
The two shared big-time aspirations and a duplex on North George Street for $320 a month -- "I could never forget that price," Rosenthal said. They idolized Penn alum Rich Hofmann, who already reported for the Philadelphia Daily News. And they hoped they could one day cover a major sports beat at one of the large metropolitan papers.
"Working for the Daily Record was really a cool and fun time," Rosenthal said. "John and I didn't know what the heck we were doing. ... We were writers, but we were also putting out the section -- which was huge, like 10 or 12 pages a night. I would get in the office at 1 in the afternoon and still blow deadline."
"We were terrible," Rosenthal laughed. "We couldn't get there early enough in the day."
The "low man" in the department, Rosenthal remembers covering high school sports and remembers covering an adult league baseball game in which he "must have misspelled six names." He got yelled at but kept coming back for more.
"The thing I remember most about York, pound for pound, it's probably the best paper I worked at," Rosenthal said. "We had a very young, talented staff. We got the most out of the paper and we had competition in the city (from The York Dispatch) that really put a charge in everyone."
After a year in York and about two years at the Courier-Post in Cherry Hill, N.J., Rosenthal became the Orioles beat writer for the now-defunct Baltimore Evening Sun and later a columnist for the Baltimore Sun. At a time when Baltimore still had no NFL franchise, Rosenthal focused most of his attention on the O's and baseball. He became a respected voice in baseball and accepted a job as the national baseball reporter for The Sporting News in 2000.
"Ken was always a terrific reporter; he wants to know everything there is to know," said Dellapina, who now works for the NHL after covering the New York Rangers for the New York Daily News from 1994 through 2008. "And he wasn't just concerned with the seamhead details -- baseball's nuts and bolts. He wanted to know about people. He understood that early on. I had to learn that and everyone in the business has to learn that.
"Kenny was always good at trying to get that and now he brings that to his viewers in a clear and entertaining way."
For years, Ken's wife, Lisa, insisted he could work in television, and eventually offers came from ESPN. Rosenthal accepted an offer from Fox in 2005. He's now a TV guy, but admits he still considers himself a writer. The world found out that Cardinals slugger Albert Pujols needed elbow surgery last week, and Rosenthal the reporter and writer had the news first.
His on-camera work is an extension of what he's been doing behind the scenes for more than two decades. He works the phones, works the clubhouse, works his connections and tries to find the answers to all those questions.
"The transition (to television) has not always been easy," Rosenthal said. "I'll prepare about 10 topics for each game, but depending on what happens I could use three or none of those topics."
He seems thrown by the whole turn of events in his own life the past few years. All he wanted to do was work on a major sports beat. And he landed that years ago. But more offers kept coming, and most nights he has a pinch-me moment: Is this really happening?
"Fox gave me this great opportunity to be the field reporter with Joe Buck and Tim McCarver," Rosenthal said. "And to this day that blows my mind."