I think this whole situation with his fitness is down to one of two things
1 - He's got a nagging injury/illness we don't know about that's preventing him from doing the required work to up his stamina
2 - He's not pushing himself enough to get that required fitness
I honestly think a lad like him should be able to have more wind than he does
I don't think he's not trying when he actually gets on the pitch, but I find it hard to believe there's not more he could be doing off it to improve in the areas in which he needs to improve, and that has to come under "attitude" (or "self-application" if you think "attitude" is unfair or incendiary)
I'm not saying he's a tit or a trouble maker like, but surely there's something going on with his application to be that unfit? At the end of the day, whether people like it or not, the PL is a fast paced league and you simply have to be able to run a lot, and if you can't do that you're going to struggle, no matter how talented you are
To be fair, he hasn't played over 60 minutes since September. Assuming he got a kick up the arse about his fitness at the start of the season, we haven't seen him given a chance to show that he's worked on it. Improving your fitness takes at the very least a few months.
You may be right, of course, but I'd be interested to see how he looks after 70 minutes now. I'd expect a pacey, quick-footed winger to be a lot less effective after that stage of the match, but if he can get to the point where he can be at near 100% for those first 70 minutes, then he needs to start I reckon.