Alexis Sanchez's days as an Arsenal player are well and truly numbered.The Gunners caused a few surprises this summer when they opted against selling the Chilean to Manchester City, despite an offering of £50 million, in the knowledge he could later leave for free.Whether or not Arsenal will procure a fee for Sanchez in the upcoming January window or milk his contract until its summer expiration is unknown, but his future looks set in stone.Furthermore, there's great reason to suggest that Arsene Wenger's gamble of holding onto Sanchez in the summer has blown up in his face.While eight goals and three assists is no disgrace, Sanchez's form has noticeably waned from the dizzying heights of last season and that once typical passion has simmered out in recent months.The Chilean did, however, save the day for Arsenal in mid-week against Crystal Palace but not without inadvertently stirring controversy once again.Supporters were quick to notice that very few Arsenal players had gone to celebrate with their star man after his goals with Sanchez even gesticulating to his teammates in bewilderment.Are Arsenal players protesting in light of Sanchez's future or was the episode purely innocent?That's for fans to decide but what is for certain, is that Sanchez can't moan when it comes to a lack of celebration after goals this season.In fact, there are instances where the Chilean has reacted to an Arsenal goal with even less animation and joy than the likes of Laurent Koscielny and Jack Wilshere upon his own strikes at Palace.The observations come thanks to Alex Kay-Jelski of The Times who displayed 'two of many examples' this season where Sanchez hasn't shown a flinch of celebration.What's very interesting, too, is that one of the strikes was a late equaliser and he was both involved in and close to the goals himself. Check out the tweet and the videos of the goals in question:

Don't get too excited, Alexis.

There could be a perfectly reasonable explanation for the acts but the accumulation of such uncharacteristic behaviour provides good reason for pessimism.

The fiery drive that gave Sanchez such an edge and importance at the Emirates stadium is almost completely gone and the heart behind that, may already be in Manchester.

It could be a long, long January for Arsenal fans.

Do you think Arsenal were right to hold onto Alexis Sanchez this summer? Have your say in the comments section below.