Philadelphia – Tiger Woods praised fellow comeback star Serena Williams for her US Open finals run on Friday while also lauding a new commercial for former San Francisco 49ers quarterback Colin Kaepernick.

Woods, a 14-time major champion, was a runner-up at August’s PGA Championship in his comeback season while Williams has advanced to the US Open final a year after giving birth to her daughter.

Woods was singled out for praise by 23-time Grand Slam tennis singles champion Williams after a US Open semi-final triumph Thursday that lifted her into Saturday’s final against Japan’s Naomi Osaka.

After a par-70 effort in Friday’s second round of the PGA BMW Championship at Aronimink Golf Club near Philadelphia, Woods returned the favor to Williams, who would match Australia’s Margaret Court as the all-time leader in Grand Slam singles crowns with a victory Saturday.

“Serena and I talk quite a bit but what she is doing is just truly remarkable,” Woods said.

“Having a child and having all the duties of a mother and trying to come back and trying to play at the elite level and she’s doing it. That’s back-to-back finals. That’s pretty impressive.”

Woods also supported a new advertisement by his sponsor, Nike, that featured Kaepernick, who has been unable to find an NFL job since launching the anthem kneeling protest movement in 2016.

Nike selected Kaepernick to star in commercials for the 30th anniversary of its “Just Do It” slogan.

The campaign, which made its television debut during the NFL season opener Thursday, has been greeted with videos of show burnings and complaints from US President Donald Trump.

But the ad has the backing of many top athletes, Williams and NBA superstar LeBron James appearing in the video, and the message – “Believe in something, even if it means sacrificing everything” – drew praise from Woods.

“I think Nike is trying to get out ahead of it and trying to do something special and I think they’ve done that,” Woods said.

“It’s a beautiful spot and pretty powerful people in the spot.”

Asked if he was consulted or contacted regarding the release of the Nike advertising campaign, Woods said he knew nothing about it.

“They did not tell me it was coming,” he said.

“When corporate does things that are outside of golf and outside of my realm, that’s what they do.”