Ruben Amorim bizarrely insisted his AC Milan defenders have ‘work to do’, despite keeping a clean sheet in their latest victory.The ex- Manchester United boss kept up his 100 per cent record with the Serie A giants as they clinched a 2-0 home win over Venezia.Ruben Amorim is yet to drop points with AC MilanGettyAfter a frustrating first half, the Rossoneri broke the deadlock on 69 minutes through club-record summer signing Goncalo Ramos.This was the Portuguese striker’s first goal for the club since his reported £60million arrival from Paris Saint-Germain.And Milan made sure of the points in the dying moments, when Ardon Jashari burst through the middle and drew a save, only for it to rebound off Venezia defender Redouane Halhal for an own goal.The result saw Amorim continue his perfect start at the San Siro, having now won his first two competitive matches in charge.Milan clinched a hard-fought 2-1 victory over Torino in their league opener, and after overcoming Venezia on Friday night, they have now moved top of Serie A before their rivals play over the weekend.It marks a promising start for Amorim, as he looks to rebuild his career in Italy after his high-profile sacking by Man United.Brutal assessmentDespite a hard-earned three points and clean sheet against Venezia, Amorim was less than impressed by his backline afterwards.The Portuguese bizarrely took aim at his back-three, and claimed they had been ‘like spectators’ at times during the win.He told DAZN Italia: “We need to improve the way we defend crosses in the box, and have to spend time in training on that. “When we are attacking, the centre-backs have to think the game is different, it’s about preparing the transitions. Goncalo Ramos scored his first goal for Milan since leaving European champions PSGGettyAmorim was less than impressed with his back three, who have conceded just once in their first two league gamesAFP“Sometimes they are just looking at the play, like spectators waiting to see what happens in front of them.He added: “We want to push forward, we left our half completely free, we mark man to man, so we have a lot of work to do.”Familiar story?Amorim’s frustrations with his defence come as he looks to implement his 3-4-2-1 set up in his new Milan side.He was often criticised for this approach during his time as United boss, with the former Sporting CP boss unwilling to change his formation.Against Venezia, Milan played a backline of Mario Gila, Koni De Winter and Strahinja Pavlovic, with this clearly Amorim’s preferred three.Much like his time at Man United, the manager has made his player preferences clear, having reportedly made England defender Fikayo Tomori available for sale despite being a mainstay since moving to the San Siro in 2020.Fikayo Tomori looks to be on his way out of Milan this summerGettyWith his future appearing to lie elsewhere, talkSPORT understands Aston Villa have placed Tomori on their list of transfer targets.Continuing to highlight where his team must do better, Amorim said: “It’s easy to understand the game. “I already said it would be a very tough match for us, because of the way they play the game.“We know the first game at San Siro, everyone is expecting us to go and get a goal fast, then we leave strong strikers one-against-one.“We had more chances to score, but we never had long periods of possession, we never calmed down the game, and that was a little bit what Venezia wanted. “We managed some things well, this game shows we have a lot of work to do, but we won and that is important.”