Sir Trevor Brooking and Stuart Pearce have warned the Premier League that new rules forcing clubs to name seven substitutes for top-flight matches next season could ruin the careers of young English players.

Brooking, the FA director of development, and Pearce, the England Under-21 coach, are concerned that clubs will stockpile young players to make up the numbers on the bench, instead of sending them out on loan to gain first-team experience. Last season players such as Fraizer Campbell, of Manchester United, and Scott Sinclair, of Chelsea, were instrumental in transforming the fortunes of Hull City and Crystal Palace respectively. Under the new rules they could be kicking their heels on the sidelines instead of kickstarting their careers.

“If the new rule stops players going out on loan, it's definitely a bad thing,” Pearce said. “You have to look at the pros and cons. On one hand Premier League managers are going to have more options when it comes to making substitutions, but the downside is you're going to have young players who will hardly ever get to play.”

When Pearce was manager of Manchester City he was responsible for the development of players such as Micah Richards and Michael Johnson, but he is worried that the new rule will hamper the development of the next generation of youngsters. “Managers will be taking 20-man squads to away games next season,” Pearce said. “There will be 11 players on the pitch, seven on the bench and two in the stands in case of emergencies. We're going to have players who are doing nothing. It's something that has to be addressed.

“At City I had calls all the time from other managers who wanted to take my players on loan. Managers are going to be more reluctant to say yes now. The size of some of the squads is going to be frightening.”

Tottenham Hotspur proposed the change at a Premier League board meeting in February. Managers will still use only three substitutes, but the new rule increases their options and brings the Premier League in line with the Champions League.

“I'm not convinced about the new rule,” Brooking said during the Under-19 European Championship in the Czech Republic, from which England were eliminated in the group phase on Sunday. “It won't help young players if they don't get on the pitch. I wouldn't want to train every day and then be stuck on the bench every Saturday. We're not producing enough good technical players and that problem is not going to be solved if the best ones are struggling to get a game.”