Trump wants to see NFL return by Kaepernick 'if he's good enough'

US President Donald Trump said on Friday he welcomes an NFL return by Colin Kaepernick, but only if the quarterback who started the kneeling protest during pre-game US anthems proves himself worthy.

Kaepernick has not been hired by any of the league's teams since opting out of his contract with the San Francisco 49ers in March 2017, settling a collusion lawsuit against the NFL six months ago.

It was Trump who called out Kaepernick and other players who kneeled for the anthem in a September 2017 rally, saying each protester was a "son of a bitch" and they should be fired.

Trump said the protest disrespected the nation and the flag, while Kaepernick had said from the start his kneeling was a way to protest racism, police brutality and social injustice.

Trump's comments pushed more than 200 players to sit or take a knee the following week, fanning much greater awareness of the move than before.

But now, Trump says he should return "if he's good enough" and that clubs would sign him if they felt that was the case, citing his relationship with Robert Kraft, owner of the Super Bowl champion New England Patriots.

"Only if he's good enough. If he's good enough," Trump said.

"And I think if he was good enough -- I know the owners, I know Bob Kraft, I know so many of the owners -- if he's good enough they would sign him.

"So if he's good enough, I know these people, they would sign him in a heartbeat. They will do anything they can to win games.

"I would like to see it. Frankly I would love to see Kaepernick come in -- if he's good enough. But I don't want to see him come in because somebody thinks it's a good PR move. If he's good enough, he will be in."

At the moment, Kaepernick hasn't even sparked a look from a franchise willing to see what he can do, a fact the 31-year-old passer noted in a video he released Wednesday on Twitter of him working out with the caption: "5am. 5 days a week. For 3 years. Still Ready."

A counter shown on the post noted he had not been in the NFL for 889 days.

And far from a public relations boost, bringing in Kaepernick could produce criticism for any team from fans who adopted Trump's view about the motives behind his protest, no matter how he fared on the field.

The latest moves comes as teams begin pre-season games to trim down their rosters for the league's 100th season, which begins next month, with all clubs testing talent at quarterback and other positions.