San Francisco 49ers linebacker Chris Borland walked away from the NFL at the age of 24 for fear of head injuries, despite not having a diagnosed concussion for a decade. And then there’s Wes Welker, the anti-Borland, a wideout with a disturbing array of concussions who isn’t ready to quit.

“As long as I’ve recovered the right way and everything like that, I’m ready to go,” Welker told ESPN in December. “I really don’t see any problem with it.’’

But apparently the rest of the NFL sees what Welker doesn’t. Pro Football Talk reported the receiver has “generated no buzz” on the free-agent market. Welker, who will turn 34 in May, is a shadow of the player he once was after sustaining three concussions in a 10-month span.

Welker was targeted just 4.7 times per game with the Broncos in 2014 and caught only two touchdowns (down from 8.4 and 11, respectively, the prior season). His 484 receiving yards were his lowest total since 2006.

In Welker’s first season in Denver, he got concussed twice in a four-game span, lying face down and writhing in pain after the second, sustained on a forearm to the head by Tennessee safety Bernard Pollard.

He sat out the last three regular-season games, and came back for the postseason wearing a bigger helmet. He proceeded to get yet another concussion on a hit by Houston safety D.J. Swearinger.

Sports columnist Jeff Pearlman wrote: “I don’t think you’re courageous. Or tough. I think you’re f—ing stupid. … Wes, you’re a young guy, and you need to retire right now.’’

Borland was diagnosed with concussions in eighth grade and his sophomore year in high school (playing soccer), and thinks he might have had one in training camp last year as a rookie. He walked away willingly. Welker doesn’t have any intention of quitting.