Filippo Inzaghi believes Milan must improve their capacity to grind out victories as they prepare to host Atalanta in Serie A on Sunday.
Milan have been inconsistent this season, with just six wins from 18 league outings so far in 2014-15.
Those results see them lie eighth in the table, four points behind the European places and five adrift of the final UEFA Champions League qualifying berth.
Inzaghi's men began their Coppa Italia campaign on Tuesday and advanced to a quarter-final meeting with Lazio courtesy of a 2-1 home success over Sassuolo.
The coach was pleased to have secured their passage to the last eight, but says his players cannot rely on performing well every week to earn points in the league.
"We're happy to progress, but let's now think about Atalanta," he told the Milan Channel.
"The second half against Sassuolo and first half against Torino [a 1-1 draw on Saturday] weren't up to the standard of our expectations.
"Big sides have to know how to win even playing badly. When we play well, we win well. Oppositely, if we don't play well we're often not able to get a result.
"It's not always easy to play well, we have to win in other ways. This is what we have to improve on."
Giacomo Bonaventura, meanwhile, is keen to shift his team-mates' focus back to the league after their Coppa triumph.
"All of the matches are now important for us, we must recover the points that we have dropped," he said.
"We're focused on the upcoming matches. We have to prepare well."
Inzaghi has fitness doubts over Mattia de Sciglio (foot) and Sulley Muntari, who is to have a scan on a muscular problem but even in the absence of those two Milan will start as favourites against a struggling Atalanta outfit.
Stefano Colantuono's men lie just a place and two points above the drop zone, without a win in four matches.
They looked set to end that sequence last time out, but Dejan Lazarevic's last-minute equaliser earned fellow strugglers Chievo a 1-1 draw and robbed Atalanta of two crucial points.
Defender Gianpaolo Bellini was sent off after receiving two cautions in that game, and will therefore miss Sunday's visit to San Siro.
