The Spaniard scored the only goal of the game from the penalty spot in injury time to give the Reds a 1-0 win over Kristiansund in Oslo - our fifth victory in a row this summer.
“To be honest, we’ve been training quite hard,” Mata told MUTV after the match at the Ullevaal Stadium.
“The first two-and-a-half weeks were quite physically tougher than last season. Obviously, the results have been better also, winning every single game.
“But I think it’s good also for Ole and for his staff to have a full pre-season where we can play the way he wants us to play.