According to his twitter after the match he posted;
"Can't believe it,, I'll never forget this day,, debut against Liverpool and should of had a pen! Fans were unbelievable today #utv"
I think playing raised his confidence and morale even more. It's good that he see's the lack of penalty and possible the yellow as unjust. It's when players dwell on stuff it becomes and issue.. He's young though he won't focus on the negatives.