Lukaku is starring on-loan at Everton this season.
The Mirror says Martinez originally asked about Senegalese star Ba, who had been a target for the Goodison club under then-boss David Moyes before joining Newcastle from West Ham.
The Toffees had been tipped off that the 28-year-old could go and wanted to beat Arsenal for his signature, ideally on loan.
However, Chelsea blocked that move and revealed that Lukaku, who scored 17 goals on loan at West Brom last season, would be available instead - and Everton came up with the best terms to borrow the 20-year-old Belgian.
A source close to Martinez revealed: "It only came up about 3 o'clock on the final day. Fortunately, everybody was able to push it through in a hurry."
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