Oldham manager Paul Dickov said it was difficult to defend his players after seeing them go down 4-1 at Bournemouth.
Lewis Grabban struck a hat-trick for Bournemouth and Charlie Daniel scored their fourth with an 81st-minute header before Matt Smith got an 86th-minute consolation for Oldham, whose latest setback was their third in succession to Dickov seething.
Dickov said: "The second half was embarrassing. To concede goals like that was embarrassing and we can't blame anyone but ourselves. I said to my players if you are mentally weak it does not matter how good a player you are.
"If they do not concentrate for 90 minutes they might as well not be there. I think they are all good players, but I have to question their mentality.
"I come out here to defend my players, but I look a bit stupid backing them after that. Bournemouth are a top team, but we cannot use that as an excuse for our second-half performance.
"A lot of my players say they want to play in the Championship, but you could see why they are not."