Everton are currently in 16th place in the Premier League table, and take on Arsenal later today.
Everton sold Lukaku to Manchester United during the summer transfer window for a huge fee, but they have failed to find a new number nine to replace the Belgian forward.
Lukaku scored the bulk of Everton’s goals last term, and without the 24-year-old, the Toffees have looked toothless going forward.
Everton focussed on bringing in a raft of number 10’s, rather than an out and out goalscorer during the summer transfer window, and that decision already seems to have backfired on Koeman.
Everton are currently in 16th place in the Premier League table, after a disastrous start to the campaign.
And Gray feels that Everton’s failure to bring in a new centre forward has been the biggest error that Koeman has made at Goodison Park.
“It’s really bad management that it was allowed to happen without — and I’m not going to say a replacement, because you can’t replace someone like Lukaku unless you’re paying £80m or £90m back out — but they left themselves really bare by not doing something to ease the blow of his loss,” Gray said.
“That would be Koeman’s biggest sin this summer. The manager has to carry the can for that — it was no secret, we all knew he was going and knew months before that it was happening. He did too.
“There are plenty of strikers around Europe who might have cost £30m, £35m, even £40m who would have come to Everton and eased the loss.
“Then a good coach has to find a way of replacing 25 goals and getting other players to up the ante.
Koeman’s job is now under severe threat, with Everton needing to find the winning formula sooner rather than later.
Everton face a tough challenge later today, when they take on Arsenal at Goodison Park.
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