$\{$Team$,$ Day$\}->$ Opponent

$\{$Opponent$,$ Day$\}->$ Team

$\{$Team$,$ Player$\}->$ Number

$\{$Team$,$ Day, Number$\}->$ Player

$\{$Day$,$ Team, Opponent, Player$\}->$ Position $,$ find minimal cover, and whether this relation set satisfies $3$NF$,$ if not, give $3$NF decompose