Chelsea signing Gareth Bale could see the side dominate for years to come, according to Gary Neville.
Chelsea wrapped up the Premier League title on Sunday, adding the trophy to their Capital One Cup success in March.
The Blues have been top of the table throughout the campaign, and are 13 points clear with three matches of the season remaining.
Bale's future at Real Madrid, meanwhile, has been the subject of conjecture, with Chelsea one of the clubs reportedly monitoring his situation.
And former Manchester United defender Neville has warned Chelsea's Premier League rivals that the addition of Bale at Stamford Bridge could see them an even more dominant force.
Neville said on Sky Sports: "If he [Bale] does become available, if Chelsea win that battle and let's say they lose Oscar, or Ramires, or a player like that for £50-60 million, and they get him [Bale] for a net cost of £25m I think the rest of the teams are in trouble for the next couple of years, I really do."
Last week, Chelsea defended their FA Youth Cup title, with the side's youngsters being tipped for a bright future, and owner Roman Abramovich was reported to have been in attendance for their latest win over Fulham on Monday.
Neville added: "Apparently Abramovich has been at the under-21s game today. They've won four of the last six Youth Cups, that is Jose Mourinho's big thing now, longevity at a club and bringing those young players through.
"He's got fantastic young players. He said earlier on in the season he would be a failure if he didn't bring those young players through.
"If they get Bale and start to bring through the best young talent in the country, which they've got, the rest could be in a little bit of trouble in the next three or four years. They are going to have to act quickly on this."