Does Chelsea have a Diego Costa problem?

Sometimes, it's the meaningless games that teach you the most.

We learned a few things from Chelsea's unexpected 3-0 loss to West Bromwich Albion on Monday, and all of them seem to spell trouble for the Blues' near future.

Chelsea have already clinched the Premier League title, while West Brom will place somewhere at the bottom end of the amorphous "mid-table" region – the real estate located comfortably above relegation danger but well below contention for European places.

This game, then, the 37th of the 38-game season, didn't mean much. But it got feisty all the same. Saido Berahino ran into the path of a square ball at the top of the box in the ninth minute and artfully curled it around Thibaut Courtois to open the score. Chelsea then grew frustrated and the proceedings grew contentious.

In the 28th minute, Cesc Fabregas got himself sent off – but we'll get to that – and then, in the second half, the hosts ran up the score.

Just after the break, Berahino was chopped down in Chelsea's box from behind by John Terry and converted his own penalty. Then, just after Loic Remy carved some space open for himself but smacked his shot off the far post, coming an inch or so short of putting Chelsea back in the game, Chris Brunt put it away for good. He found a good deal of space at the edge of the box on a short corner and blasted his effort in at the near post.

Chelsea's final big chance, in the 73rd minute, when Nemanja Matic run onto the flick-on from a corner at the far post, was denied by goalkeeper Boaz Myhill.

And so Chelsea suffered just their fourth loss of season.

But there were other implications.

1. Tactics

It had seemed in recent months that Jose Mourinho's men could probably play nice soccer if they wanted to – as they did last year and early on in this campaign – but were choosing to play it safe. On Monday, with Chelsea opening up and attacking far more than they had for some time, it seems like their tactical choices were less cynical than they were necessary.

We won't get carried away with affixing meaning to a solitary game with no impact on the standings, but it seemed Chelsea were played apart fairly easily when they got more adventurous. It's no wonder Mourinho stood along the sideline looking mighty cranky after the 3-0. (Which didn't stop him from celebrating with the away fans following the game. Oh well. Jose being Jose.)

2. The case of Diego Costa

When properly handled and harnessed, like Atletico Madrid did last season, the heavy-browed Costa is a weapon. But when he's deployed without the requisite caution, he becomes reckless and a liability.

Fabregas's sending-off was precipitated by Costa manhandling West Brom defender Gareth McAuley. He first elbowed him in face, then wrestled with him some more. McAuley understandably took exception. And as the West Brom players spoke to the referee, Fabregas pinged a ball at the scrum, beaning Brunt in the back of the head.

The Brazilian striker set the tone for this animosity, and it didn't serve Chelsea at all. That sort of stuff was sometimes helpful on Atletico, a team that was often overmatched in the important domestic games and on the continent, but Chelsea has no use for the combativeness of underdogs. They can outclass just about any team.

Costa's 63-minute return from yet another injury – the burly target man seems to somehow be made of glass – produced very little of substance. After a red-hot start at the club, he scored 19 goals in just 23 league appearances this season. But he was also suspended three games for a stamp on Emre Can in January. Perhaps Chelsea should wonder of his bull-in-a-china-shop style is suitable for every kind of game.

3. Fabregas could be suspended for three games

Following his sending-off, word on the broadcast was that Cesc would be charged with violent conduct. If the match report bears that out, he faces an automatic three-game suspension, which would render him ineligible for the first two league games of next season – Chelsea can appeal, but stand little chance.

That would be a blow. Because Eden Hazard may be Chelsea's architect, getting the plaudits, but Fabregas is the general contractor, doing the actual building of attacks.

(It's worth noting here that Terry and Costa probably deserved red cards as well.)