Mitroglou? The funny thing is he's been relatively decent in terms of output since then
Yes, that's the one!
They have the worst defence i've seen in the league though and that's what has relegated them.
The attack isn't exactly great either since the goals dried up for Mitrovic. Still, a solid defence and they'd have a chance of survival but like you say it's been awful.
The backline is really lacking PL experience, perhaps something they should've looked at.
Mawson and Chambers have some but are still youngish, and don't have that much playing time in the division behind them. Mawson ultimately got relegated last season, as did Chambers the lats time he played much when on loan at 'Boro. Le Marchand is new to the country. Odoi, Bryan and Christie have never played at this level before. Ream has but it was only briefly and long time ago. Fosu Mensah doesn't have a great deal of experience.
That lot in front of a goalie who hasn't inspired confidence and an expensive midfield who haven't provided much protection isn't likely to work out. They could have done with a leader or two in the 27-31 sort of age group with plenty of high level games behind him. They had money to spend so I'm sure I could have found players to fit the bill.
Edit: Even sticking entirely with what they had might've been better, at least it would have been a well drilled unit.