Manchester United boss Ole Gunnar Solskjaer has some "hard decisions" to make this summer if he is to revive the club's fortunes, according to Jaap Stam.
The Red Devils have been a fading force since Sir Alex Ferguson's departure in 2013, with noisy neighbours Manchester City replacing them at English football's summit.
A sixth-place Premier League finish this term saw United hit a new low, with no trophy or Champions League qualification to show for their efforts under Solskjaer.
The Norwegian was brought in to replace Jose Mourinho on an interim basis back in December, who was dismissed after a disastrous first half of the 2018-19 campaign.
After overseeing 14 wins from his first 17 matches in charge, Solskjaer was rewarded with a three-year contract, but results took a major turn for the worst thereafter.
A major rebuilding job has been mooted at Old Trafford this summer, with a number of incomings and outgoings expected while the transfer window is open.
Stam, who returned to the Theatre of Dreams for a treble reunion charity match against Bayern Munich on Sunday, has advised Solskjaer to stamp his authority on the current squad in order to affect real change.
"I think we definitely could do with some more quality up front, in midfield and the back four as well," the ex-United defender told Sky Sports.
"You want a squad that is competitive towards each other. Everyone needs to push each other to get the maximum out of everyone - to achieve something.
"As a manager and as a club, you need to have a look at that. After the last couple of seasons and how everything is going, I think it is good to re-evaluate everything in the team.
"Look at the players, what they have done and what they have achieved. Even players who have a contract for another three or four seasons - you need to make your choices towards them and what you want to do with them.
"At the end of the day, the most important thing is to achieve the goals you set out, sometimes you need to make hard decisions to do that."
United have been linked with a number of high profile transfer targets since the end of the season, not least Ajax defender Matthijs De Ligt, who had been touted for a £65m ($83m) switch to Old Trafford.
The club have since ruled out a move for the teenager, however, with a series of departures thought to be on the cards before reinforcements are brought in.
Antonio Valencia and Ander Herrera will move onto pastures new upon the expiration of their contracts in June, while the futures of David de Gea, Juan Mata and Paul Pogba are still very much up in the air.