Thorgan Hazard
Chelsea fans may not have seen the last of Thorgan Hazard at Stamford Bridge. Getty Images

Chelsea have confirmed the sale of Belgian midfielder Thorgan Hazard to Bundesliga outfit Borussia Monchengladbach.

Hazard, younger brother of Stamford Bridge favourite Eden, initially moved to Borussia-Park in July 2014 on a season-long loan deal but has now completed a permanent transfer to Germany for a reported €8m fee after failing to register a single first-team appearance during a three-year stint at Stamford Bridge.

The Premier League leaders do not appear to have totally given up on the 21-year-old, however, with the club keen to stress in their official statement that the deal to sell Hazard includes an option for Chelsea to buy the player back in the future.

Examples of such clauses being exercised in recent years are admittedly scarce, with Real Madrid swooping to re-sign Daniel Carvajal from Bayer Leverkusen in June 2013 perhaps the most high-profile example, but Hazard may well take hearty encouragement from the career trajectory of former teammate Nemanja Matic.

The Serbian international returned to Chelsea in January 2014 in a £21m deal just three years after being sold to Benfica as part of the agreement that saw David Luiz first arrive in English football, and has since gone on to establish himself as one of Jose Mourinho's most important players.

Hazard, who has one senior cap for Belgium and spent two full seasons back in his homeland with Zulte Waregem between 2012-14, has made 27 appearances in all competitions so far this season for Gladbach under Lucien Favre but clearly did not do enough to convince Mourinho that he was yet worthy of a place alongside his supremely talented sibling in Chelsea's first-team squad.

While the Blues have not provided firm confirmation of the exact fee involved in Hazard's departure, if the €8m price being touted is indeed accurate then the club's hierarchy certainly deserve credit for making yet another significant profit on a player who cost them a measly €500,000 back in 2012.