While Ramirez did not suffer an injury, a poor decision on the bases moments later cost the Cubs a scoring opportunity in their 2-0 loss to Milwaukee.
With the Cubs trailing by two, Ramirez banged a pitch from Chris Capuano off the right-field wall.
But he didn't run hard to first base as he watched the ball, then turned on the burners when he saw it bang off the wall.
Ramirez tried to stretch his double into a triple but was easily thrown out at third on a throw from right fielder Geoff Jenkins.
Manager Dusty Baker said Ramirez was trying to be too aggressive.
"Anytime you get a leadoff double Aramis was hustling to third," Baker said.
"Everybody says he doesn't hustle, then he was hustling. He just hustled at the wrong time."
Was Ramirez hustling to first base?
"Not really," Baker said. "I'm sure he was watching the ball. In that situation you just can't get thrown out at third base with nobody out."
Ramirez conceded Baker was right.
"I didn't think I hit it that well, but when I saw the ball carry, I started running," he said.
" Everything we do looks big because of the way we're playing. Guys get thrown out every day.
"Somebody gets thrown out for us and it looks big because we're not scoring runs."
The Cubs are now 9-21 against left-handed starters and have yet to score off of Capuano in 26 innings in three starts.
Asked before the game to explain the Cubs' problems against left-handers, Baker blamed the absence of Derrek Lee for most of the season.
"Without D-Lee there, he was our left-handed equalizer," Baker said.
"Wasn't D-Lee one of the top left-handed handed maulers in the league last year?"
True, Baker was told, but so was Ramirez, who has been in the lineup for all but three games.
"Exactly," Baker said. "But if you have both of them, if one [doesn't] get you, the other one will."
The "other one," Ramirez, came into Thursday's game hitting .189 against left-handers in 2006, the fourth-worst average in the National League.
Last year Ramirez hit .355 against lefties, ranking third in the league, and led all NL hitters with a .694 slugging percentage against lefties.
Ramirez "is trying to drive in 20 runs in one at-bat," Baker said. "That's what I talked to him about today."
Lee hit .333 against lefties last year, eighth in the league.
The Cubs finished 1-2-3 in the league in slugging percentage last year, with Lee (.673) and Michael Barrett (.624) following Ramirez.