Scholes was speaking after United lost 2-1 to Sevilla in the Europa League semi finals.
And he believes if United had extra firepower in the lineup or off the bench, they would have won the game.
United had twice as many shots as Sevilla, but were unable to take their chances, and got caught on the counter twice.
"If they want to win trophies, they've got to start spending the money," Scholes said on BT Sport.
"They've created chances tonight but if Sancho's in that team they'd have scored."