Ruben Amorim said that Manchester United will have to “suffer for a long period” before their fortunes turn after his first game in charge ended in a disappointing 1-1 draw at Ipswich.

The new head coach has only had a few days to work with his full squad after the international break and he felt that they struggled to absorb the numerous positional changes he demands in his 3-4-2-1 system, saying they over-thought it.

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Marcus Rashford put United in front after two minutes but Omari Hutchinson equalised just before half-time. Ipswich might have won but for a clutch of fine saves by the United goalkeeper, André Onana.

“It’s hard to expect anything now,” Amorim said. “It’s not a surprise but you have to see it in-game. That’s why I was a little bit anxious because you cannot understand what will happen in the game. I felt that. They are thinking too much because things are so different.

Roy Keane became embroiled in an angry exchange with an Ipswich fan on Sunday. While off air for Sky Sports’ punditry team on the Portman Road pitch, Keane came in for abuse from a supporter who barracked him as ‘a better pundit than manager’. Keane, who was Ipswich manager from 2009 to 2011, stormed over to the fan in the stands and repeatedly shouted that they should ‘discuss it in the car park’.

“It’s hard for the players in three days to cope with everything but we [must not] forget about the new idea. That’s why I was brought here and we try to cope with the things they are used to doing. Next year, in the same stage, we will be here with the same problems or we start now … we risk a little bit, we suffer a little bit and in the next year we will be better.

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“We start very well but then we should have more possession. Sometimes, we had the ball in defence and the rest of the guys were too stuck because they were thinking: ‘Where should I be?’ They need time to have some fluidity. I know it’s frustrating for the fans but we are changing so much in this moment with a lot of games. We are going to suffer for a long period. This will take time. We could lose if it was not for Onana so we have to understand that and be pragmatic that these guys had two days to train to change so much.

“We will have a situation where you see a structure and you will say: ‘It’s not fluid.’ But it is like [taking] steps. We have to put in the heads the structure. When they start thinking about the structure they will play so much better.”