In a statement, Mr. Skipper implied that the sudden talent loss was little more than business as usual and not an indication of any vulnerability at ESPN.

“We are confident in our relationship with fans and comfortable with change,” he said in a statement. “We have a deep bench and a bright future.”

ESPN said that it bid competitively to keep Mr. Cowherd and, in a farewell to him, Mr. Skipper breezily said: “Endings also bring new beginnings, for ESPN and Colin, and we thank him and wish him the best."

It is not unusual for networks to lose stars — just not this quickly. Comedy Central has had much more time to absorb the departures of two of its biggest names within a matter of months. Stephen Colbert left “The Colbert Report” last December to prepare to take over David Letterman’s late-night slot at CBS on Sept. 8. And Jon Stewart will leave “The Daily Show” next month.

ESPN has watched some of its own people leave for other networks over the last 35 years, like Rich Eisen, Craig Kilborn, Dan Patrick, Erin Andrews and Mr. Olbermann, who left angrily in 1997 to join Fox Sports Net.

Perhaps to show that it is still a powerhouse, ESPN has gone out of its way in the last year or so to announce contract extensions with prominent on-air personalities like the anchors Bob Ley, a stalwart almost since the start of the network, and Scott Van Pelt, as well as the analysts Jay Bilas and Jon Gruden.