Former Formula V8 3.5 champion Tom Dillmann will make his Super Formula debut with Team LeMans next month.
Dillmann will fill in for Pietro Fittipaldi at the Autopolis and Sugo rounds, when the Brazilian has clashing commitments in IndyCar.
Williams Formula 1 junior Oliver Rowland had also been in contention for the full-season seat, having tested for the squad at Suzuka last month, but lost out to Fittipaldi.
Dillmann’s Super Formula outings could come on top of a full campaign in the FIA World Endurance Championship.
The 29-year-old participated in the Prologue last week for the ByKolles LMP1 squad, after expressing his intention to race with the team.
ByKolles, which will field a single ENSO CLM P1/01 in the WEC superseason, has only announced Oliver Webb as one of its three drivers so far.