Patrick Cutrone came off the bench to score twice as a below-par AC Milan battled through to the Coppa Italia quarter-finals with a 2-0 extra-time victory at Sampdoria.

After a forgettable 90 minutes at the Luigi Ferraris, Cutrone side-footed home from Andrea Conti's teasing centre and followed that up with another fine finish to earn a scarcely deserved win for the Rossoneri in the additional time.

Sampdoria will feel they created the better of the chances against a Milan side that lacked creativity and ideas until Cutrone's introduction, but Pepe Reina made crucial saves from Riccardo Saponara and Albin Ekdal when it mattered.

The win is unlikely to do much to ease the seeming ever-present rumours that Gennaro Gattuso's position as head coach is under threat, although they can at least look forward to a last-eight tie with either Napoli or Sassuolo.

Milan had a let off in the 23rd minute when Jakub Jankto's dipping right-wing cross was spilled by Reina and Gianluca Caprari's claims of a push by Cristian Zapata in his attempts to reach the ball fell on deaf ears.

Gonzalo Higuain wastefully drilled wide of the left post after getting in behind the defence and the lacklustre nature of the match continued until Hakan Calhanoglu wasted a glorious 70th-minute chance from Samu Castillejo's right-wing delivery, somehow squaring across goal instead of turning the ball home at the back post.

Higuain then rightfully had a goal ruled out for offside, and Fabio Quagliarella fired wastefully into the side-netting for Sampdoria before ex-Milan man Riccardo Saponara placed an effort wide of the bottom-left post.

Reina came to the fore in extra-time, first brilliantly closing the angle to deny Saponara before a brilliant double save denied Ekdal and Dawid Kownacki.

Those interventions proved crucial when Conti, whose time at Milan has been injury plagued, put one on a plate for Cutrone to guide past Rafael, and the Italy international lofted another expert finish over the goalkeeper from Calhanoglu's pinpoint pass to seal the win.

What does it mean? Gattuso needs more convincing performances

Perhaps a little ring rust should be expected after a mid-season break, but even taking that into account Milan never reached a level above underwhelming. Being a club legend might buy Gattuso more time than any other coach, but you really do wonder if Milan, Coppa Italia finalists last season, will be tempted to try and coax the likes of Arsene Wenger or Antonio Conte to San Siro in the near future.

Reina wonders set up late winner

Conti, still working his way back to fitness, and Cutrone combined off the bench, but had it not been for Reina's big saves their moment of inspiration could not have happened. The former Liverpool keeper was a bit shaky early doors, but a series of huge saves – including one from Kownacki with the score at 1-0 – proved crucial.  

Bakayoko and Co. lucky to progress

You could make a case for about eight or nine of Milan players to have the dubious honour of worst player of the game. Calhanoglu was cumbersome and indecisive, Higuain tried hard but still looks well off the sort of form that made him one of the best strikers in world football and little came from either full-back. But Tiemoue Bakayoko just about takes it for a largely anonymous performance that included several instances of misplaced passes. 

What's next?

Milan will now travel to Saudi Arabia where Wednesday's Supercoppa Italiana contest with Juventus takes place, while Sampdoria visit Fiorentina a week on Sunday in Serie A.