In the last day or so, it has been revealed that 19 year-old international goalkeeper Thibaut Courtois is set to move to Chelsea from Belgian champions Genk. But with more and more promising youngsters leaving Stamford Bridge and an ageing squad, the London title challengers and their new manager Andre Villas-Boas are going to have to increase their investment in young players if they are going to maintain their high playing standards in future.

Chelsea seem to have a habit of letting talented young players go. Perhaps it’s because of the amount of funds they have to buy mature players who can instantly slide into the first team, but as the remnants of Jose Mourinho’s back-to-back title winning squad fade and the ages of key figures like John Terry and Frank Lampard slide up and up, it’s strange to see so many youngsters leaving Stamford Bridge in recent years.

If Roman Abramovich is to fulfil his ever elusive dream of winning the Champions’ League, then the blues must build a squad that will blossom in the future, rather than focusing exclusively on the here and now. Ben Sahar left for Espanyol in 2009, Miroslav Stoch and the pacey Scott Sinclair went in 2010, and 2011 has seen the departure of Jack Cork, Fabio Borini, and Michael Mancienne. It’s not exactly promising news for a club that often suffers for a lack of squad depth when injuries hit during the league season.

With an ever-ageing squad, it’s likely that these injury troubles will continue to get worse. In recent years, when injury has struck key players like Terry, Lampard, Essien and Cech, it’s not been uncommon to see unknown names make the Chelsea bench. The Londoners have also been forced to utilise players like Paulo Ferreira, who are past their best and – although they’re much loved for their work at Stamford Bridge during the Mourinho golden era – are getting a bit too slow for the Premier League.

So to ensure that they can continue to pose a title threat in future years, Chelsea must sign more players like Courtois, with a view to eventually replacing some of the older players in their squad. It’s only a matter of time until some of the blue veterans start to think about retirement, or moves to smaller clubs. It’s up to Andre Villas-Boas to make sure that the Premier League runners-up are given a much-needed injection of youth to safeguard their future. Chelsea fans will be hoping this happens before it’s too late.