Nemanja Vidic and Rio Ferdinand's injury problems held back the development of current Manchester United defenders Chris Smalling and Phil Jones, according to the Serbian defender.
Ferdinand and Vidic forged a fearsome partnership at Old Trafford between 2006 and 2014, winning five Premier League titles, three League Cups, the Champions League and the Club World Cup.
Smalling and Jones were signed by Sir Alex Ferguson as long-term successors to the exceptional duo, at the ages of 20 and 19 respectively.
However, Ferdinand and Vidic struggled for game time in Ferguson's twilight years, with the Englishman dealing with back issues and Vidic suffering a serious cruciate ligament injury in 2011.
Jones and Smalling were thus left without a mentor alongside them at Old Trafford, and Vidic - the last United captain to win the Premier League - has expressed regret at his inability to guide their development.
"It didn't help them [Smalling and Jones] because they didn't have a more experienced player to pick their brain when they played," Vidic said, per ESPN. "It's not just about playing together with an experienced player.
"If Phil Jones is 24 and playing alongside someone who is 34, the player who is 34 years old is using his brain more than the 24-year-old.
"To rise, he needs to be encouraged a bit and made to feel comfortable in his shoes.
"If you lose that belief and think: 'Should I be here, or here, or be here, then it's difficult to play.
"So that didn't help them. Even if they do something bad, you say: 'OK, he's 24 but where was I to help him?"
Vidic moved to Inter in 2014, before eventually retiring in 2016, while Ferdinand spent a season at QPR prior to his retirement in 2015.