One option is to just ignore the whole thing and expect employees to show up like normal. Another might be to negotiate: Let workers adjust their schedules to watch the games in return for making up the lost time in some other way. Both these tactics would minimize disruptions to the workday. But they also might be a missed opportunity.
A third approach is to take a cue from the Dutch football legend Johan Cruyff, who once said: "The attack is the best defence." In that spirit, why not turn on the office TV and invite employees to watch the games together? True, not much work will get done. But think of it as an opportunity to improve engagement, cultivate a stronger sense of community, and build up some goodwill for the longer term.