Manager Manny Acta ruled out the prospect of Hafner, who has not seen the field in a game since 2007, playing first base to keep his hot bat in the Tribe's lineup.
Hafner entered Thursday batting .375 (9-for-24) with two doubles, four home runs and eight RBIs over his past eight games. Pronk has posted a 1.442 OPS since June 8.
"It wouldn't be fair to him," Acta said. "What are we going to do? Hit him one million grounders today so he'll be ready tomorrow? He doesn't get defensive work."
Right shoulder woes have plagued Hafner in recent seasons, sapping him of the power that once made him one of the most feared sluggers in the American League.
Acta plans to award Hafner one at-bat per game on the upcoming trek, which includes stops in Pittsburgh, Philadelphia, and Cincinnati.
"We don't want him to go a long time without seeing pitches," Acta said.