Spurs booked their place in the quarter-finals with an 8-7 triumph in the shootout following a 2-2 draw after extra time.
Eight of Tottenham's nine penalties found the net, but Villas-Boas says that his side have not practised spot kicks at all this season.
"We practised and practised penalties for the Basel game last year, but we didn't this time," Villas-Boas told reporters.
"We haven't practised them for three or four months."
Prior to last night, Spurs had not won a penalty shootout since beating Peterborough United in 1994.