But that was before an 8-0 humbling administered by a Boston team that possesses a better record than the White Sox and is pushing for an American League wild-card playoff berth if it doesn't win the AL East.
"We don't hit, we don't play defense and we don't pitch," Guillen said. "That's the result. I think it feels like we had another day off. Now we have two days off in a row. Hopefully we show up [Saturday] and play better."
The Sox were blanked for the 10th time while being held to a season-low two hits for the third time.
Although the Sox still lead the AL Central, they have allowed 19 runs in their last two losses. That helped raise Guillen's sense of urgency.
"You try to avoid those games, and hopefully they don't happen often," Guillen said. "But we're in a situation now where they are must-win games, and we cannot sit here and say it's another game and it's OK.
"We have to go as hard as we can. We have been fighting for five months, and we have one month left. Now we have to throw the biggest punches we can, and hopefully one lands and we knock somebody out. That's the way we have to approach every day."
The Sox also were victimized by a four-hit game from Dustin Pedroia, who hit his 41st double for Boston.
"It's amazing how this kid shows up to the park every day and plays the way he plays," Guillen said. "He brings a lot of energy. Right now that kid is the key to their ballclub."
Vazquez kept the Sox close until the sixth.
"We have to forget about this and come back," he said.
Guillen has insisted it's easier to win the division than land a wild-card berth. But he would accept either as long as the Sox reach the World Series, potentially against the rival Cubs.
"It would be great for the city," Guillen said before the game. "I think if that happens, the Chicago mayor ( Richard M. Daley) would have a really good chance to have the Summer Olympics there (in 2016). I guarantee you, because that city's going to go crazy. To the players it would be awesome, to the fans, but I don't know for me and Lou (Piniella). It should be unbelievable."
But Guillen wouldn't mind playing a World Series there under certain circumstances.
"Playing the Cubs, why not?" Guillen said. "They have a good ballclub. I think they have a lot of talent. But I think for the city, I think it would be outstanding."