The fans. Everyone in the crowd is given a button for which line goes out, and when to pull the goalie. People online can help the refs decide what is or is not a goal, penalty or when to put a spotlight on an opposing player as they enter the attacking zone.
It's part of the new fan-based-initiative (FBI) so all those people who claim to know be able to do a better job than the coach get their time to shine.
That's not new; the St. Louis Browns did this in 1951. They ran a "Manager For A Day" promotion that produced two winners, but the league told the team that it couldn't be done. So the team decided to give all the contest entrants seats behind the dugout and use their input to set the lineup, batting order, and any substitutions that would need to take place.
Funny thing is that part of the fans' lineup involved a big chance (putting Sherm Lollar in as the catcher; his playing time behind the plate had been cut after the team acquired Matt Batts). Lollar had a good 1950 season and looked to be breaking through, but Batts replaced him partway through the next season. Regular manager Zack Taylor liked Batts over Lollar, the fans preferred Lollar.
In the game on August 24, with 1,115 fans making the decisions, the Browns broke out of their 1-4 slump with a 5-3 victory. Lollar was 3/4 with two RBI and three runs scored. Batts went back into the lineup the next day, and the Browns lost their next five games.
The epilogue is that the Browns decided after the season to move a catcher. And so they traded Lollar to the White Sox, and he nearly immediately became the AL's second-best catcher behind Yogi Berra. The Browns continued to flounder.