There was a lot riding on Chelsea's FA Cup semi-final with Southampton on Sunday.The Premier League champions have endured a difficult second season under Antonio Conte and it looks almost certain that the Italian's reign at Stamford Bridge is soon to end.A torrid 2018 has not only seen the Blues crash out of title contention but has effectively ruined their chances of qualifying for the Champions League.As a result, the FA Cup stands alone as their only shot at silverware and Conte seemingly ending his tenure on a high.Against Southampton, there was plenty of reason to be optimistic but Chelsea didn't have it all their way against the Saints and entered the break at 0-0.

Conte subbed Willian off for Bakayoko

Nevertheless, Olivier Giroud - who scored twice against Southampton the week before - eventually broke the deadlock by drifting past two defenders and Alex McCarthy to score.

The strike brought out some rather negative management from Conte, though, and it went down like a lead balloon with Chelsea fans.

To the utter bewilderment of many supporters, Conte pulled off the brilliant Willian in the 64th minute and replaced him with Tiemoue Bakayoko.

Willian delayed the sub and walked down the tunnel

Chelsea fans had been cheering 'Antonio', one of their go-to chants, but immediately turned to booing when the fourth official revealed the details of the substitution.

What Willian did next, had football fans talking.

He was seen leaving the pitch shaking his head in what commentator Darren Fletcher branded 'a contender for the slowest walk off the pitch ever.'

He then, naturally, proceeded to walk straight down the tunnel.

Check out the Twitter reaction below:

It's very unprofessional from Willian, it's got to be said.

Despite the victory from Chelsea, which was extended by an Alvaro Morata strike, there's still the feeling that all isn't well at Stamford Bridge right now.

There was a similar incident between Conte and Eden Hazard after the Manchester City defeat that will give supporters quite the sense of deja vu.

Whether or not Willian will leave in the summer is a completely different question, but the familiarity of a lack of Champions League football certainly won't help things.

Do you think Antonio Conte should leave this summer? Have your say in the comments section below.