It doesn't surprise me that Berahino's behaviour wouldn't be top notch. He had an opportunity in the Summer to move to a bigger club fighting for bigger goals. A club who would've tripled his wages, a club that has a number of players he has played with at England under 21 level, with a number of those now pushing through to the full England team. The chance to play for a club with a dynamic, young manager who sets his team up to play a style of football that suits Berahino down to the ground. A club who's participation in the Cups and Europe would give plenty of chances to play his favoured number 9 position. Add to this the fact that his manager at WBA actually wanted to sell him, only for the Chairman to want to get in a dingdong waving competition with Levy as he was unhappy with the way we went about trying to sign him and the timing of our bids.
Berahino does not fit Pulis' style of play at all. He knows that at best he is third choice at number 9 for WBA (and possibly even 4th) because he doesn't have the power to bully defenders like Rondon, Lambert and Anichebe (is he still there?) do, he is therefore completely unsuited to Pulis' scrappy, long ball game. He also isn't really a traditional winger who will go wide and get crosses in, so doesn't fit Pullis' idea of a number 7 or 11. Ergo he is pretty much guaranteed to be on the bench at best and even if he does come on he is having to play a style of football to which doesn't compliment his skills, which at the age of 21 is doing his career no good at all.
At the end of last season Berahino probably had an outside chance of making the England Euro 2016 squad, that chance has probably now gone. Not because of poor play or even poor attitude, but simply because his manager favours a style of football that Berahino is completely unsuited to playing. In addition to this the moment may have passed for Spurs to want him, which could lead to him either ending up at a club of lower standing or perhaps a club of slightly higher standing but with very much a bit part role.
I completely understand Berahino's behaviour and don't blame him for it. This is his career that is being set back here. For those of you that compare his behaviour with that of Luka Modric, the difference is that Modric was wanted badly by Redknapp and indeed Modric was probably the first name on the team sheet for that manager. Redknapp also played a style of football that suited Modric down to the ground. Modric was also given assurances that he could leave in another year's time for a reasonable transfer fee. Contrast this to Berahino who's chairman has denied him a £20 odd million move despite his manager not really wanting him and him being 3rd of 4th choice centre forward.