Ross was non-committal when asked if he would give the ball to Kimbrel for the ninth inning if the Cubs had a one-run lead.
Kimbrel struggled in his first two appearances this year after he had a tough time last season with Chicago.
It's a tough situation for Ross, who took over as manager in October.
He played alongside Kimbrel while the two were in Atlanta.
The 32-year-old Kimbrel is a key member of Chicago's bullpen, but the pandemic-shortened season is quite unforgiving at just 60 games.