LONDON, ENGLAND - JANUARY 13: Diego Costa (3rd R) of Chelsea squares off with Boaz Myhill (2nd R) of West Bromwich Albion after the final whistle of the Barclays Premier League match between Chelsea and West Bromwich Albion at Stamford Bridge on January 13, 2016 in London, England.  (Photo by Clive Mason/Getty Images)

Chelsea 2-2 West Brom: 5 Things We Learned

​Chelsea were denied a crucial win against West Brom on Monday through a late James McClean equalizer. 

The Blues, who have not lost a match since Jose Mourinho's departure, seemed to have things under control after Cesar Azpilicueta got on the end of Branislav Ivanovic's cross to score the opener. But West Brom, had other ideas, coming from behind twice to claim a 2-2 draw.

Tony Pulis must be proud of the effort which earned his team a point at Stamford Bridge, but for Chelsea, it was definitely two points lost.

Here are five things we learnt from the heated clash between these two sides.

5. Costa Still a Work in Progress

​Diego Costa's game is much better nowadays, and so is his attitude. The thin-skinned striker has been mostly concentrating on his football, but couldn't keep it all under control against the Baggies.

He got into a minor tussle with Jonas Olsson during the match, and would also engage the keeper, Boaz Myhill, after the last whistle, as his frustration got the better of him.

Hiddink's methods have left visible changes in Costa's deportment, however, he's not all watered down just yet and still needs a bit of work. 

4. Berahino Doesn't Seem to Have a Future at West Brom

​A few months ago, who would have thought that Saido Berahino would be coming off West Brom's bench in an important game against Chelsea? The forward was a major threat up front for his team last season, but can't even start a match despite the Baggies' struggles this term. 

His desire to leave the club over the summer has obviously made things difficult and it doesn't look like he will be getting back into the side anytime soon. If he is to live up to all the expectation, he needs to make a quick exit.

3. Hiddink Isn't Exactly Midas

​Chelsea's season took a positive turn with the arrival of Guus Hiddink, but the team still isn't completely fixed. 

The Blues struggled to hold on to leads under the Mourinho regime, dropping several points from winning positions. And although things are much better under the new boss, they can't seem to shake this ailment off.

Two leads were surrendered to West Brom on Monday, and they almost lost to Watford after letting one slip away late last month. This is one area Hiddink will have to pay lots of attention to if he wants to make another mark at the club.

2. Fabregas and Costa Partnership Blooming Once Again

​Cesc Fabregas and Diego wreaked havoc on the Premier League last season, giving the Blues an early push which set them up for the rest of the campaign. 

The connection between the two players was quite apparent, with Fabregas assisting a large number of the forward's goals. But this season, it hadn't been so fruitful, until now. 

Although there were no goals or assists from either one on Monday, the service was evident and would lead to the Azpilicueta's opener. If the pair can keep the lines open moving forward, the Blues can still make a real push up the table.

1. Matic Is the New Mikel... And Vice Versa

​Nemanja Matic now faces an uphill battle getting back into Chelsea's starting 11. The Serbian is the one player who was poor under Mourinho and is still poor under Hiddink. 

Fortunately for the Blues, an unlikely hero in John Obi Mikel has stepped up to do what Matic failed to do all season. He's made himself quite useful since being pushed back into the team and has been a dominant force in the midfield as of late.

Mikel put in another great shift on Monday, cleaning up in front of the defence with his break up play and neat passing. Matic on the other hand, came on as a late substitute to help shore things up, much like Mikel used to under Mourinho.

Barring a sudden dip in form or injury, to the Nigerian, Matic won't be in Hiddink's plans for the better part of the remainder of this season.