ESPN prides itself, we’re led to believe, on its courageous reporting on sports-related issues.

Which brings up the question: Why did the nation’s No. 1 sports network bail on a PBS project that examines the outbreak of concussion-related trauma being suffered by professional football players?

Was it pressure from the NFL, with which ESPN has a long-standing — and highly lucrative — financial partnership? It smells like it.

Frontline is an award-winning documentary series broadcast by PBS. The program, based out of WBGH-TV in Boston, is set to air a two-part series called “League of Denial,” in which it looks at the concussion rate among NFL players and examines whether playing professional football has become hazardous to the health of its participants.

The early indicators are that the concussions are becoming a grave concern.

ESPN was supposed to be a partner in the project. It backed out this past week. ESPN said the NFL applied zero pressure to the network, even though there have been reports of a extremely testy meeting between ESPN and NFL Commissioner Roger Goodell.

Two plus two still equals four, correct?

OK, the news isn’t all bad.

Frontline will present the broadcast, even without ESPN’s participation. It airs on Oct. 8 and 15, and will be shown in the Texas Panhandle on KACV-TV, the region’s public television station operating on the Amarillo College campus.

ESPN does its share of in-depth sports journalism, particularly with its “Outside the Lines” specials. They produce occasionally riveting and, if you’ll pardon the pun, hard-hitting examinations of the lives of prominent athletes.

As the network has shown, though, in cratering on the Frontline project, it is capable of missing a tackle or two.