The move brings Detroit's starting ranks from six pitchers to five after Monday's day-night doubleheader. What it means for Bonderman's return from shoulder problems remains to be seen.
Willis is winless in his last four starts with an 8.53 ERA and 16 walks over 19 innings since holding the Rangers scoreless over 6 1/3 innings May 19 at Comerica Park. However, Willis has competed on the mound to make his stuff work, a facet possibly never more evident than his outing Tuesday against the White Sox.
Despite five walks and five hits over as many innings, Willis held Chicago to three runs, leaving before Detroit eventually pulled it out. He seemingly injured his right knee sliding into home plate for a tag attempt, then made his final out with a diving stop on the first-base side of the mound and a throw to first from the ground.
Once Willis' knee was fine Wednesday, manager Jim Leyland's decision was made.
"I think Dontrelle certainly deserves to go out there Sunday," Leyland said. "I really like the way he competed."
Willis' outing came a day after Bonderman made his first Major League start in a year, taking a loss against the White Sox with six runs on eight hits over four-plus innings. Three of those hits were home runs.
It has been a slow process for Bonderman to regain his velocity after surgery last summer to correct a blood vessel restriction in his right shoulder, and his fastball topped out at 91 mph Monday. He spent his Minor League rehab assignment trying to learn how to focus more on changing speeds and locating rather than being the power pitcher of his past. That process will continue from somewhere other than Detroit's rotation.
Bonderman was in the bullpen Tuesday night with a shortened Tigers relief staff, but Leyland said nothing about Bonderman's role going past this series.
Jason Beck is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.