When you are a journalist, you try to be as objective as possible, and while sometimes it is difficult, owing to your obvious leanings towards a favourite team, at the end of the day, you do your job and try and sleep well in the night, thinking you have done it.

But then, there are some instances, when you struggle to prevent your heart from making those words appear on a page.

So, here I am watching Chelsea play Arsenal in an English Premier League game, wanting Arsenal to win, but also prepared to wax lyrical about Chelsea if needed (hey, they play some good football often enough).

Then comes that moment, just before halftime, when a man called Diego Costa shows everything that is wrong with modern football, with referee Mike Dean falling for it hook, line and sinker.

Nobody takes it to the edge as much as Costa, and that is not a problem if you do not cross the line, but at Stamford Bridge on Saturday, Costa crossed the line, and then some, and despite all that, he somehow stayed on the pitch, with an Arsenal player sent off.

Justice would have been Costa seeing red the moment he struck Laurent Koscielny with a flaying arm with his right hand and then immediately after that with his left, before, pretending like he was the one wronged and going in and barging into Koscielny.

Anything resembling justice would have been if Costa would have been sent off along with Gabriel – hey, after receiving a yellow card, you cannot do anything remotely daft, and he did, with Costa luring him better than a mermaid would a fisherman.

I sometimes wish Arsenal would be more like other teams, you know go that extra mile to milk a situation and ensure the opposition is punished.

Koscielny should have gone down like Costa would have, or indeed the majority of modern footballers, when the Spain international – what irony aye, that Spain, who play the most beautiful football, now have this guy as their leading striker – hit him on the face not once, but twice, with the second one definitely worthy of a straight red card.

But Arsenal don't play like that – they are that team who always believe in just getting on with the game, and don't try to play on the referee – yes, yes there are some times when they do, but for the large part, they don't -- and put him under pressure. Had they been different, you never know, Gabriel would not have even gotten involved enough for that red card to come to fruition.

Costa has been compared to Luis Suarez for the manner in which he gets under the skin of his opponents, but even Suarez did not play this dirty -- apart from a bite or two of course.

There is something about Costa that is eminently unlikeable, and he is not even on the level of Suarez so that you can try and forget those failings.

He is a good striker, but nowhere near as good as Suarez was during his time in the Premier League with Liverpool, or is with Barcelona right now, where he keeps making Lionel Messi and Neymar better players.

While Suarez is that movie villain you kinda cannot hate, Costa is the villain you loathe, and I know I am speaking for every single fan not supporting Chelsea.

You should not go into a match looking to send an opposition player off, you, plain and simple, must not – surely winning is not that important; it shouldn't drain the life out of this beautiful sport, and while that might be going over the top a little, you just wish all teams would go back to playing pure football, or at the very least, fair football.

Too much to ask?

Surely not.

Here we have fans paying ridiculous amounts of money to watch one Premier League match – let alone a whole season – and isn't it the job of the teams, managers and the players to ensure they maintain a basic ethical standard, or is that asking for too much in this modern era, when winning, no matter how, is all that matters?

The answer was given by the Chelsea fans really, when cries of "Diego, Diego, Diego" rang out at Stamford Bridge when he was finally taken off by Jose Mourinho.

No doubt, most teams' supporters would have done the same – still doesn't make it right, though, or fail to leave anything but a bitter taste in the mouth.