Coach Filippo Inzaghi said AC Milan still have a "great deal" of work to do after suffering a second successive defeat on their preseason tour of the U.S.
Milan lost 3-0 to Olympiakos in Toronto on Thursday before going down 5-1 to an inexperienced Manchester City side in Pittsburgh on Sunday.
Serie A traditionally kicks off two weeks after the Premier League and other major European leagues, meaning Milan are not as prepared as their opponents at this stage of preseason.
But Inzaghi, who replaced Clarence Seedorf as coach this summer, believes his players have plenty of room for improvement.
He told Milan's official website: "It's in front of everybody's eyes that we have to improve in lots of areas. We've not been working long and we come off the back of an eighth-placed finish. We have to work a great deal.
"We didn't do too badly in the first 10 minutes. We did well in terms of possession and less so without the ball, which we've focused less on. I'm disappointed because we conceded those two goals after creating chances.
"Without the ball, we're not nasty enough -- we need to react more when we lose it. Work is the only thing that will allow us to be competitive soon. It's down to me to watch the match again and ask for more from everybody.
"[Mario] Balotelli had a good game. We asked a lot of him because he only arrived on Monday. He was ready to play 45 minutes. We need to work on his fitness step by step, and we will try and bring everyone up to the same level.
"It's never nice to lose like this. The players have to now train well and get back to playing better as soon as possible."
He said his players' current fitness levels "can't come close to the English sides, but we certainly have to give that something extra."
And he added: "The blame lies with me and I will take it. I will continue working with this squad, and when we're all in shape and we have everyone we definitely won't be the side from the past two matches.
"Clearly we could have shown more concentration and determination, and it's down to me to ask for more of this in the next match.
"I think that once we're a complete group we can be competitive in the league. We'll get back on track. We have to concede fewer goals -- we must improve on this aspect."