His side overcame Wigan Warriors 32-22 just weeks before the two teams meet at the Tottenham Hotspur Stadium.
Watson was pleased with how the Giants performed after both teams rotated players.
He said: “It was a weird game to be fair. The amount of changes both teams had made it feel like that, but I think the way our squad approached it and their mentality going into it was outstanding.
“There were some guys who stood up and showed some really good performances. The thing we spoke about today was showing how good our squad was, and that we can win even when we do make changes.
“I’m always a little bit edgy when there’s five minutes to go, because you can still score a couple. We needed to be better defensively at times, we weren’t probably working hard enough for each other. We allowed them to come back into the game.
“With the amount of changes made in this game, I see this as a separate occasion to the final. Come two weeks it’ll be a different mentality altogether.
“There will be a different type of energy buzzing around the ground.
"We want to get to the final and have won the games so when it’s over we’re still in a good spot in the league as well. We want a good run at the playoffs this, and we know it’s about getting yourself in a good position.”