Manchester United have spent big this summer by signing Jadon Sancho and agreeing a deal to bring Real Madrid defender Raphael Varane to Old Trafford, but former United skipper Roy Keane is not convinced that will be enough for them to mount a push for the Premier League title.
United boss Ole Gunnar Solskjaer is under huge pressure to mount a push for the title as he enters his third full season as manager a few weeks after signing a new three-year contract to continue in the role.
Yet Keane told Sky Sports' The Overlap that his former club are still short of challenging Manchester City and Chelsea at the top of the table, as he suggested David De Gea will be a weak link if he starts in goal this season.
"I still have my doubts," he said of United. "The couple of signings they have made have been fantastic and there's no doubting the quality they've brought in but I'm still worried about the middle of the park.
"I have a feeling United will pull something out of the bag in the next few weeks. They need someone in the midfield. Scott McTominay is a good young player who's improving.
"There's talk of them moving to a 4-3-3, but the middle of the park in that No 6 role worries me. People talk about recruitment at clubs and it's also about shifting people on. Sometimes you are waiting for a couple of players to go out as United have a lot of players in the background.
"They've got the likes of Jesse Lingard. They're not the answers. I don't think he's done enough to warrant re-entering the fold, but football's about opinions.
"I don't think Lingard is going to get United back challenging for titles, and I'd say the same for Fred. Jesse did well at West Ham and perhaps they're a good fit for him.
"When you talk about winning league titles over the past few years, United have come up short. They've not even been close to winning. United have a huge problem with the goalkeeper."
Keane is backing Manchester City to reign supreme again, in a summer when they have spent £100million to sign Jack Grealish and continue to pursue Tottenham striker Harry Kane.
"When you think back to the first two or three months of last season, we were writing off Man City," he recalled. "We thought they'd lost their way and that they'd lost their hunger. But they then went on a great run in the new year and they were fantastic.
"It made you think why we even doubted Pep Guardiola, but if they get Kane - he's guaranteed 20-25 goals. Grealish is a good age at 25 and Pep will want to work with him and improve him. If Kane goes to Man City, it'll be very difficult to stop them.
"I'm always interested to see how clubs do with their new signings. With Jack Grealish going to Manchester City, it'll be interesting to see how Aston Villa do.
"You're always keen to see how the promoted teams do, and when football is in your blood you just look forward to the games. The fans being back in just brings an energy to the stadiums. It's always interesting to see who can win the league."
He also backed European champions Chelsea to take strides forward this season, after they smashed their transfer record to bring striker Romelu Lukaku back to the club.
"Chelsea have always had the quality and when you look back at the end of last season, you saw there was plenty of energy with the new manager coming in with new ideas. But they've always had quality players.
"A bit like City at the moment, they've been crying out for a natural goalscorer and Romelu Lukaku gives them a great chance. A bit like Kane, he guarantees goals. I know Liverpool have a lot of players coming back but I'd be looking at Man City and Chelsea.
"Unless Liverpool or Manchester United pull something out of the bag in the remaining couple of weeks of the window. I can't see beyond City or Chelsea."