Massimiliano Allegri admits the Champions League will provide the truest test of whether Juventus' heavy recent investment has been a success.

The Italian champions splashed the cash on Cristiano Ronaldo and brought Leonardo Bonucci back to the club from AC Milan in the off-season in an attempt to end a 23-year wait for a European crown.

Comfortable victories over Valencia and Young Boys have set them on the right course in Group H, while an early six-point advantage atop Serie A should afford Allegri the chance to focus closely on continental matters.

The 51-year-old guided the Bianconeri to the Champions League final twice in his first three seasons in charge and now has hope of securing the one trophy to have eluded him.

"For sure the squad has improved significantly in quality thanks to the club's investment," Allegri told a news conference.

"We will see at the end of the season, based on how much we have won, whether the team is stronger.

"We've won a lot over the years and only the Champions League is missing. It's not easy, it takes luck and other right components."

Juve's simultaneous chase for an eighth straight Scudetto takes them to 14th-place Udinese on Saturday.