Everton manager Roberto Martinez has suggested that the club needed to sign Romelu Lukaku last summer.
The Belgian became the Blues' record signing in July after netting 15 times during his loan spell from Chelsea in 2013-14.
However, Martinez believes that Lukaku's signature was integral to keeping the Toffees moving forward.
He told the Liverpool Echo: "When you work with Rom you know he is the best possible ambassador for the role in our club. He has had many, many games last season that we knew, in order for us to progress, we needed to keep Rom here.
"Of course, it was not that straightforward at all. There was a lot of work behind the scenes, the chairman was very influential, we were very lucky to have the experience and contacts of our chairman.
"We also had to produce that sort of money and we had to make that it available to invest in one player."
Lukaku scored Everton's winning goal in the first leg of their Europa League last-16 tie against Dynamo Kiev on Thursday night.
Chris O'Keefe
