The 27-year-old entered F1 in 2011 as the series' reigning champion, and he is now returning to Mercedes, for whom he raced throughout his four-year DTM career.
"It is emerging that MercedesÂ may ask di Resta to act as reserve driver for their F1 team, which will make him back-up to Lewis Hamilton and Nico Rosberg," the correspondent for the Times newspaper, Kevin Eason, said.
Di Resta will kick off his DTM return immediately, with a test beginning on Tuesday.
"It feels really good to be back in the DTM and to see so many familiar faces again," he said.
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