The Spanish playmaker has been largely under-utilised so far this campaign at Stamford Bridge under Jose Mourinho despite starring for the Blues last season
Ahead of the game against the Swiss side, Blues manager Jose Mourinho claimed that Mata deserved to play, but he couldn't do so because of the level of competition in the team rather than any personal issues with the Spaniard.
Chelsea eventually ended up losing 1-0 in Switzerland, with Mata staying on the bench as he watched Kevin de Bruyne, Eden Hazard and Fernando Torres come on instead.
Named the club's Player of the Year in both seasons he has played in since arriving in 2011, Mata has struggled to break into Mourinho's starting line-up this season after the Portuguese manager returned to Stamford Bridge.
The 25-year-old has made only seven league appearances, with two of those as a substitute, as both Eden Hazard (12) and Oscar (12) are both preferred to him in the attacking midfield slots. Mata has started eight out of 10 matches he has been involved in but has only finished a match once, and was a unused substitute in a further seven matches.
This is despite Mata registering 20 goals and 35 assists in 64 games last season - a superb return from the playmaker.
While the former Valencia man has insisted previously that he is happy to accept Mourinho's decisions, speculation that Mata is not part of the flamboyant coach's plans has not gone away.
With speculation that French moneybags PSG are ready to move in for Mata in January, a majority of Goal Singapore readers feel that he should leave Chelsea.
A whopping 89% believe that he should seek first-team football elsewhere, which would be crucial as next year is a World Cup year and playing regularly would boost his chances of making it to Brazil. The remaining 11% feel that he should bide his time and try to prove himself worthy of a regular starting spot again.
With the transfer window due to open in slightly over a month's time, it will be interesting to see whether Mata stays or leaves.