Smith forged a friendship with Kap when the two were teammates in San Francisco ... and he said this week he just doesn't understand how his old pal can't find a team.

"It still doesn't make sense," Smith told NFL Network star Kyle Brandt on the "10 Questions With Kyle Brandt" podcast.

Alex says Kaepernick's talent level, even during his rookie and sophomore seasons, was obvious ... and the NFL seemingly refusing to give him a job over his past kneeling demonstrations during national anthems is just perplexing.

"The run that he went on, at the end of that last year that we were together [in 2012] and went to the Super Bowl ... was so crazy to watch," Smith said. "Truly one of the historic runs in football to see what he was doing."

Smith continued, "It's crazy to fast forward only a couple years after that and he was out of the league. It's hard to -- you couldn't even grasp it. Couldn't understand it. You couldn't."

Smith said it's "so tragic" how some in the NFL and others in the country didn't realize what Kaepernick was protesting back in 2016 ... explaining, "He was ahead of his time."

"The country wasn't ready. Nobody was ready for it. And, he's sitting there trying to tell everybody through a completely peaceful manner about some of the things going on in this country and that have been going on for a long time."

Smith continued, "And, to see the backlash that happened, yeah, it hurts. It hurts looking back at it that the country wasn't ready for it and he suffered the repercussions."