The reason Gregory asked the players with yellow cards to raise their hands was that he wanted to make a few changes during the halftime break and he wanted those to come off to be among the players already booked so as to reduce the chance of his team getting a red card in this game.
It turned out those he wanted to remove were among those with yellow cards so that was a good thing as he could bring on the players he wanted to bring on and launch his tactics regarding the second half.
After a good halftime rest, the second half was set to resume and the players being aware of that were making their way to the pitch.
"Welcome back, everyone, the second half of the game is about to kick off as we can see both teams making their way to the pitch now." Tony articulated.