Unless we can get what we paid back for him, which is doubtful, then I think he deserves another season, under a new manager, who will hopefully get the best out of him, and hopefully he will be fitter, stronger and more confident this season.
For me, we are already starting to do the right things, in shifting the deadwood out. Gomes, Livermore, maybe Siggy, Dawson, Rose, Naughton Lennon, etc, all of which means that we can afford to give Lamela the benefit of the doubt.
Sure, if he fails under Pochettino then he will have to go, but until and if that happens, the serial underperformers are the reason we are underachieving, not Lamela.