Chelsea reached the FA Cup fourth round courtesy of a routine 2-0 victory over Nottingham Forest. 

Almost a year to the day that the Championship outfit caused an upset against Arsenal, Maurizio Sarri will have been pleased to avoid that particular banana skin. 

However, a quick glance at the scoresheet revealed something a little more unusual, and that was a brace for Alvaro Morata. 

The 26-year-old has only scored five league goals this season, proving a major problem for the Blues.

In contrast, Harry Kane has contributed 14, Pierre-Emerick Aubameyang 14, and Mo Salah 13 - so Morata's stats make worrying reading. 

Saturday's two goals, albeit against second-tier opposition, ought to have given him reason to celebrate.

Instead, the Spanish international was noticeably subdued. 

Below are the highlights, including both his strikes - the second brought a few high-fives with his team-mates but he failed to raise so much as a smile. 

Plenty of Chelsea fans initially noticed his downbeat attitude and Marca have now offered an explanation. 

Who was his behaviour aimed at? 

The Spanish outlet claim that Morata's decision not to celebrate was a deliberate dig at Sarri's assistant, Gianfranco Zola, who he feels has not been giving him enough respect. 

Zola has implored him to improve tactically, quoted via Sky Sports this week: 

"Technically Morata - and this is the reason we invested a lot in him this year - we thought he was the perfect number nine for us.

"I think he has to improve a little bit tactically because nowadays with the type of football, football is so organised you need to get better tactically, your ability is not enough.

"In my opinion he needs to improve on this. He's been working on that, he has a good attitude. He feels that he doesn't score enough and he feels a lot of responsibilities for that.

"But he has to learn to put everything behind because these are only burdens that you take on the pitch and they don't help you to perform better."

Unfortunately, Zola has said little that can be interpreted as unfair there. Morata has not taken it well, nevertheless. 

It's fair to say he didn't quite silence his critics either, missing an open goal from four yards. 

As the striker considers his future, Sevilla, Borussia Dortmund, and Bayern Munich are among the clubs willing to take him on. 

In turn, Chelsea are thought to be pursuing one of Gonzalo Higuain, Edinson Cavani, or Callum Wilson. 

Do you think Chelsea have shown Morata enough respect? Have your say in the comments.