Charlton chairman Les Reed has aimed a swipe at Iain Dowie saying he is partly to blame for the club's slump in form.
The Addicks' season hit a new low on Tuesday when they crashed out of the Carling Cup to League Two side Wycombe at The Valley.
The defeat saw the fans turn on the players and also call for Alan Pardew to replace under-fire boss Les Reed.
Murray admits Reed has not been good enough so far having won just one of his six games in charge.
Charlton insist they will stick behind Reed and Murray blames the club's problems on Dowie's transfer flops.
Dowie spent over £11million in the summer, but Murray believes the players he brought in have failed to shine.
"Les is getting hammered at the moment and it is a tough spell for the club. Very tough," said Murray
"We have to see some changes on the pitch - we were awful against Wycombe. But those who watch Charlton regularly will say maybe it was the same under Iain Dowie. Maybe we haven't got a good enough squad.
"At the moment, we are carrying on as we are. We have got three key games coming up against Middlesbrough, Fulham and Aston Villa - and then we'll make some changes to the team in January.
"It is unfair on Les at the moment. His current record is similar to Iain's - not good enough. But are both managers at fault? Or maybe there is not the right balance in the squad.
"We will spend some money in January but we will have to wheel and deal, although we definitely won't be selling Darren Bent. We spent a lot of money in the summer - £11m we didn't have to spend.
"We backed Iain, they were Iain's signings - but I had never heard of (Souleymane) Diawara, apparently the best centre-half you've never heard of.
"For a club like ours to spend £3.7m on one player like that is a fortune.
"Some people must not just look at Les but what went on before.
"Also, maybe Alan Curbishley had that ability of getting a bit more out of some players than his successors have."
Murray also played down talk that the club could make a move for former West Ham boss Alan Pardew to replace Reed.
"People say why don't we get Pardew next, but maybe he needs some time out of the game," added Murray.
"And a lot of people are saying that Pardew's key was his assistant, Peter Grant."