The Argentine striker is refusing to write off his side\'s chances of topping the pile but admitted that the team\'s busy schedule played a role in the their downfall.AC Milan striker Maxi Lopez has conceded that his side face an uphill task to retain their Serie A crown.The Rossoneri find themselves three points behind leaders Juventus with only four matches remaining, going into Sunday\'s contest at Siena.\"It will be hard to win the Scudetto, but we are not giving up,\" the South American attacker is quoted by MilanNews.it as saying.\"Siena will be a tough opponent right now because they are doing well at a physical level.\"It is a shame that we lost the lead we had, because we went from four points clear to being three points behind.\"We have been playing every three days for the last three months and it is not easy to keep up this pace.\"It is not over yet and we will not give up, hoping that Juventus will slip up.\"The marksman, who is on loan from Catania, has scored two goals in 11 appearances.\"I feel just fine here. I am always available and I try to be ready when the coach needs me,\" he concluded.