Harry Maguire said it's vital Manchester United get their summer recruitment right while warning that he's seen players arrive during his time at Old Trafford that could not handle the pressure that comes with representing the club.
Maguire has committed his future to United by signing a new one--year contract with the option of an additional 12 months.
He believes last summer's recruitment drive to bring in Bryan Mbeumo, Matheus Cunha, Benjamin Sesko and Senne Lammens has narrowed the gap with the likes of Manchester City and Arsenal.
But he's told club bosses it's crucial last summer's business is backed up with more quality arrivals.
"I always want to be part of a squad that I felt like could compete and the recruitment went well last year, we brought in some top players who helped us," Maguire said.
"I think this summer's going to be a big summer, I think we've got to recruit really well. Obviously there's a big manager decision as well, but I think the recruitment side of it is bringing players in.
"I think this summer has got to be a big year because we're not in Europe this year, we've played 40 games at the end of the season, and we definitely need a bigger squad next year."
United have regularly got their recruitment wrong in the 13 years since their last Premier League title with big-money signings often struggling to make an impact.
Maguire has seen first-hand how some expensive arrivals have flopped during his seven years at Old Trafford.
And he's told the club that any new addition this summer must be able to handle the intense spotlight and scrutiny which comes with wearing the United badge.
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"I see a lot of players come into this club and quite frankly it's just too big for them," he said.
"The eyes on, the scrutiny, the analysis, every goal that goes in. It's someone's fault. There's going to be ex-players speaking about it. That's just part and parcel of playing for this club."
United have been in Ireland this week to prepare for Leeds United's visit to Old Trafford on Monday.
Michael Carrick's team head into the weekend third in the table. But Maguire believes that, with the right players arriving in the summer, they could challenge for the title as early as next season.