The winner of the October 9 match will represent CONCACAF in the 2017 Confederations Cup. In past years, Mexico would get the spot, having won the Gold Cup in the year after the World Cup, but two years ago, CONCACAF decided that the Confed Cup spot would be determined by a playoff between the Gold Cup winners in the years before and after the World Cup. Because the U.S. won the Gold Cup in 2013, they earned one spot in the playoff, and when Mexico beat Jamaica, 3-1, in the 2015 tournament's final on Sunday, they earned the other spot.
Both the U.S. and Mexico have made the Confederations Cup a priority in recent years, seeing it as an opportunity to test themselves against top quality competition and also to get comfortable in the following year's World Cup host. The 2017 Confederations Cup is in Russia, just like the 2018 World Cup, meaning the teams there have the advantage of having competed in a tournament there prior to the World Cup.
Jurgen Klinsmann will be under pressure to win the playoff after such a dreadful Gold Cup. The U.S. could have wrapped up a spot in the Confederations Cup by winning this year's Gold Cup, but they crashed out in the semifinals and fell short in the third place match for their second-worst Gold Cup finish ever. If the Americans can rebound in the playoff, their struggles won't seem nearly as bad with the Confed Cup unaffected, but a loss would certainly turn up the heat on the U.S. manager.
The last time that the U.S. and Mexico met at the Rose Bowl was in the 2011 Gold Cup final. The U.S. went ahead 2-0 in that match, but Mexico stormed back with four goals to win the match and the tournament. That match saw Mexico fans make up roughly 90% of the crowd and while the growth of the U.S. fan base will probably mean more American fans this time around, El Tri will still undoubtedly enjoy significant advantage in the stands at the 93,000-seat Rose Bowl.
Tickets for the playoff will go on sale in September. CONCACAF will make tickets available to both the U.S. and Mexico federations, as well as the supporters groups, prior to the public sale. That allocation to the federations should allow for a more balanced crowd than there was in 2011.