In January, Chelsea surprised many fans by agreeing to a deal which allowed Thorgan Hazard to join Borussia Monchengladbach on a permanent basis. That deal includes an option for Chelsea to buy the midfielder back (though the specifics aren't known), and it doesn't sound as if activating that option would upset the player at all:
"I am at the right club. I can develop here, have a coach who trusts me, and I am close to my native Belgium. It remains my goal to play with my brother Eden at my dream club Chelsea one day, but for now I want to stay at Gladbach for a long time."
"Eden also knows that Gladbach are a great club for me."
While watching the Hazard brothers suit up for Chelsea together would be a lot of fun to watch, at the moment, it's a long way from actually happening. Thorgan just needs to keep working at his own game while helping Gladbach push for Champions League football, and if he develops into anything close to the player that his brother has become, he'll likely get that opportunity.