After picking up a few hits against the Yankees, Dunn went 0-for-7 in the first two games of the series against the Twins, with two walks, three strikeouts and a run scored.
"He's struggling so much right now. Hopefully, with a little break we give him, we can get something better out of him," Guillen said. "He was swinging the bat a little bit better in Chicago, but the last couple days he lost it."
Dunn has just 54 hits in 331 at-bats and a .163 average to go along with a .294 on-base percentage, and he's slugging just .302. His struggles drew national attention on Thursday when Stephen Colbert joked about Dunn threatening Bill Bergen's record-low batting average of .139.
While his continued struggles could likely be affecting Dunn's confidence at the plate, which would only compound the issue, Guillen thinks it's more frustrating than anything for Dunn right now.
"I think mentally, he should be very exhausted," Guillen said. "He's missing pitches. He's missing fastballs, he's missing changeups, he's missing breaking balls, guessing wrong pitches. Everything has piled up, one thing after another."
With two months left in the season, it's unlikely Dunn will be able to improve his poor offensive numbers. But Guillen hopes that Dunn will learn from this season and come back better prepared and in better shape for the 2012 season.
"He has to stay in shape now, he's not 22 years old anymore," Guillen said. "Now he has to learn that he has to prepare himself better. That happens to everyone. That happened to [Paul Konerko], that happened to [Mark] Buehrle."Brent Lillibridge started at first base in Sunday's 7-0 victory and went 2-for-4 with a homer, his second in two games.