Manager Rafael Benitez endured another frustrating summer in the market, ultimately bringing in seven players on budget fees, loans and free transfers.
The Tyneside giants only claimed their first Premier League win of the season last week, a 1-0 victory over Watford which provided a much-needed boost to the Toon Army's morale.
Nonetheless, Newcastle still sit just one position above the bottom three and remain level on points with 18th-placed Huddersfield Town.
And Cole, who scored 68 goals in 84 appearances for the Magpies between 1993 and 1995, has urged Mike Ashley to bolster the team's ranks and increase their chances of survival.
"That is the nature of the beast. If you look at the teams that have come up they have all invested - and even they are struggling.
"Newcastle made a minimum investment and they are struggling. They need that investment. They might be able to do that in January but we will have to wait and see."
The Magpies return to Premier League action on Saturday with a home clash against Eddie Howe's Bournemouth, who sit sixth in the table.