At the Smackdown tapings this week, Rey Mysterio became the #1 contender for Kane’s World Heavyweight Title. The reason for the Kane vs. Mysterio matchup at Summerslam, which will take place August 23, and not a Kane vs. Undertaker match is because The Undertaker still isn’t 100% recovered from his latest injury.
It’s always possible that Undertaker could be added to the Summerslam match in a triple threat, but if the current plan is for Kane to face Undertaker at Night of Champions in September.