Chelsea are in a bad place at the moment.The Blues started off the season well under Maurizio Sarri, but they have struggled greatly in recent months.Thrashings at the hands of Bournemouth and Manchester City in recent weeks means Sarri has come under scrutiny.It's been reported from multiple outlets that he will lose his job if the club's poor run of form continues.But the Italian manager is not entirely at fault.A number of players have been well below-par in recent months.One player that Chelsea fans are losing patience with is Marcos Alonso.The Spanish left-back has been one of the best in the world in recent seasons, but his form has dropped off massively this campaign.Back in September, Sarri was glowing in his praise for the 28-year-old.“Alonso, at the moment, [in] this position at left-back is maybe the best in Europe,” Sarri said, per the Independent. “Physical qualities at a top level, I think."He’s doing very well in the offensive phase. But I also think he can improve in the defensive phase. If he improves that, he could be the best left-back in the world."But ever since then, Alonso's form has been in free-fall.A Chelsea fan has now made a video of Alonso's biggest mistakes in recent months and it's gone viral.Included in the video are numerous mistakes against Manchester City, both in attack and defence, as well as his mistake for Ander Herrera's goal for Manchester United.Watch it below:In all honesty, that is hilarious. The clip has since gained 6,000 retweets and over 13,500 'likes'.Even Chelsea fans found the video funny.

Wayne Bridge took the chance to call out Alonso on Monday night after his mistake for Man United's first goal.

"When Alonso gets asked questions defensively, I’m sorry but I just don’t think his good enough,” Bridge said.

“He’s good in the attacking phase but, goes to sleep mode while defending.”

Not many Chelsea fans will disagree with that.

Should Alonso be dropped in favour of Emerson? Have your say by leaving a comment below.