Amid the gloom of an eighth-placed Premier League finish there was plenty to bring optimism to Manchester United. Sir Jim Ratcliffe’s new minority ownership lifted the club out of a malaise, even if the results are yet to be witnessed, Kobbie Mainoo proved the academy is still producing elite talent and they won the FA Cup final against Saturday’s Community Shield opponents – and fierce rivals – Manchester City.

There were, however, many reasons why the team ended in their worst Premier League position and bowed out of Europe in December. Injuries played a major part and Erik ten Hag never looked to have a definitive plan of how to achieve his objectives but another key issue was the lack of senior players having the influence their reputations demand.

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Ten Hag’s coaching staff has been overhauled but the squad is very similar to the one that stumbled through last season. The teenage defender Leny Yoro arrived to much acclaim but is facing three months out with a foot injury, leaving the forward Joshua Zirkzee as the only new face available to Ten Hag at Wembley and making it imperative to find improvements from within.

Marcus Rashford failed to make the England squad after his form fell off a cliff, Casemiro looked unable to cope with the pace of English football, André Onana had an indifferent campaign and Mason Mount had no impact. On the up side, that trio had a summer without a major tournament and Ten Hag knows he will have to rely on these players in the early part of the season while those who were in Germany or the US resettle after international action.

Asked whether it would take time for the team to find their feet, Ten Hag said: “I can see this because we didn’t have time together. We have to work on our game model to find the patterns. It was a break, they all played Euros, Copa América, so they were in different teams, with different game models and different patterns. Now we have to bring this together. It is complicated. I am not the only one who has to deal with this problem but there are also teams with less international players – they can make a proper pre-season so they are probably ahead of us. We have to deal with this in the coming weeks without dropping points.”

Last season United lost four of their opening seven league games. Victories over Wolves and Nottingham Forest were fortunate as they struggled to find anything akin to rhythm in the early weeks. A repeat performance would bring pressure on Ten Hag and the players, something they failed to cope with for much of last season.

The feelgood factor from winning the FA Cup – and final two league games – needs to continue if United are to build momentum, a concept they are unfamiliar with. The letters from America recounting pre-season friendlies will be soon forgotten and another victory at Wembley would provide the ideal platform for what could be a new era at Old Trafford.

The captain Bruno Fernandes and Lisandro Martínez, of the senior players, worked the hardest to inspire victories from poor performances last season, while others wilted. When City are not at their best, they still have players who can turn matches in their favour. It is a lengthy list consisting of Kyle Walker, Rodri, Kevin De Bruyne, Phil Foden, Bernardo Silva and Erling Haaland, among others. These are the experienced players making a difference, whereas at United that has been lacking. United outperformed City in May when it mattered but this needs to be their consistent mindset led by those who have been at the top longest.

Rashford cannot continue on the periphery of matches for a second consecutive season; he needs to be critical in the good times and the bad. He should feel mentally and physically refreshed. “We all have seen on tour he was very lively, in a very good shape already,” Ten Hag said. “We expect a lot as we expect from the whole team this season. There are so many suggestions around Manchester United. We know the truth. He is working very hard, very good, very engaged, very ambitious and motivated to make a good season.”

Next Friday United open the league season at home to Fulham, who won at Old Trafford in February and have enjoyed a more relaxing summer. Then they face a trip to Brighton before welcoming Liverpool. “We beat Liverpool, we beat Man City but our challenge is to bring consistency,” Ten Hag said.

City have lost their past three Community Shields, a glorious insignificance in Guardiola’s tenure because of the major trophies glittering on the Etihad Stadium mantelpiece. Another defeat would be met with a collective shrug in east Manchester, making the result far more important to Ten Hag as he looks to rebuild the collective mindset at Old Trafford.

“We know already we can beat City and that is not dependent on the result on Saturday, that will not change that belief,” Ten Hag said. “The FA Cup was a higher occasion than the game on Saturday. Nevertheless, we want to win but we showed on occasions we can beat City.” The challenge is set for United and they need their stars to reach for them once more.