| The 30-year-old, who was a quarterback at the 
				San Francisco 49ers for six years and sparked a national debate 
				when he knelt during the national anthem during the 2016 NFL 
				season to protest racial injustice and police brutality, smiled 
				at the cheers.
 Former 49ers safety Eric Reid, who protested alongside 
				Kaepernick and who like his former team mate remains unsigned, 
				also received a warm reception when he was also shown raising a 
				fist at a packed Arthur Ashe Stadium.
 
 "Every athlete, every human and definitely every African 
				American should be completely grateful and honored by how Colin 
				and Eric are doing so much for the greater good," Serena 
				Williams told reporters following her win.
 
 "They really use their platform in ways that is really 
				unfathomable, so I feel like they obviously have great respect 
				from a lot of their peers, especially other athletes and people 
				who are looking for social change."
 
 Kaepernick and Reid have both filed collusion grievances against 
				NFL owners and league over the fact that neither has been signed 
				by any of the NFL's 32 teams since their protests spread around 
				the league.
 
 On Thursday, system arbitrator Stephen Burbank denied the 
				league's request to dismiss the case, which means he found 
				sufficient evidence for the case to continue and perhaps go to 
				trial.
 
 The protests of the national anthem have raised the ire of some 
				NFL fans and U.S. President Donald Trump, who has said they 
				disrespect the American flag and the military.
 
 (Editing by Nick Mulvenney)
 
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