Former Caterham Formula 1 driver Giedo van der Garde is set to test DTM machinery with Mercedes next month.
Autosport understands the Dutch driver will take part in the series' traditional rookie test at Jerez in the first week of December.
Van der Garde contested the 2013 F1 season, before spending last year as Sauber's reserve.
That relationship ended with an infamous legal stand-off over a promised 2015 race seat on the eve of the Australian Grand Prix.
As he looks to return to racing, van der Garde tested a Bentley GT3 sportscar earlier this year.
Decisions about Mercedes' 2016 DTM driver line-up are believed to be on-hold until champion Pascal Wehrlein's potential move to F1 is resolved either way.
If van der Garde does enter the series, he would join fellow ex-F1 drivers Paul di Resta (racing with Mercedes) and Timo Glock (BMW) on the grid.
European Formula 3 frontrunner Jake Dennis is also set to turn laps with Mercedes at Jerez, while Formula Renault 3.5 driver Jazeman Jaafar is another likely participant.
Malaysian driver Jaafar, who shares a link with Mercedes sponsor Petronas, finished eighth in the FR3.5 standings with Fortec.