I understand his frustration but his temperament is costing him support in other areas. He's the President and sometimes discretion is the better part of valor.
I would have said something more along the line of, " Players, you are looked up to by very impressionable kids. They think of you as role models. In these troubled times, please don't confuse kids further by throwing this kind of protest in front of them."
Then I would have driven back to the WH, got in bed with Melania and said, those players are a bunch of jacko***, in the privacy of our bedroom.