Harang said he felt the tightness in his back after his second throw during pregame warmups with catcher David Ross, but had hoped to be rid of it after loosening up further.
"I thought it was just something, you know, maybe once I get loose, I'll be able to pitch through it," Harang said. "I started going out in the bullpen, came up here [to the clubhouse], got adjusted really quick before the game. It's one of those things that's better safe than sorry."
Interim manager Pete Mackanin wanted nothing to do with risking a serious injury to the team's best pitcher.
"You could tell from the first inning his velocity was off, and he just didn't look comfortable," Mackanin said. "He said that he had loosened up, but when he came out, we just said, 'That's it, we're not taking any chances.' You can't take chances with him."
Did the loss of the team's most reliable pitcher so early in the game cause Mackanin to scramble to occupy the mound for the rest of the game?
"Yes, it does," Mackanin said. "We were just feeling comfortable, because I knew that Aaron was pitching today and figured he would hopefully give us at least seven, if not eight innings, and I was going to back off on his pitch count, because his last two outings he threw 116 and 120 pitches, something like that.
"We were going to keep him right around 100 today. So, we met that goal."
It was up to the Reds bullpen, then, to complete the game's final eight innings. And with an NL-worst 5.05 staff ERA entering Saturday, the bullpen surprised few when it gave up an additional six earned runs to give Chicago a comfortable win.
Left-handed reliever Mike Gosling, who had given up just one earned run in eight innings of relief entering Saturday, replaced Harang in the second inning.
The Cubs did not wait long to take advantage of the Reds' pitching change, as Alfonso Soriano crushed a two-out, three-run home run off Gosling into the upper deck in left field to extend the Cubs' lead to 5-0.
"I didn't take that couple of seconds that I needed to get myself together mentally, and I think it cost me there in the second inning," Gosling said. "Just kind of getting ready physically, quickly, but I didn't take the time to settle myself down, and by the time I did, I'd given up those three runs."
Gosling returned after the second with clean third and fourth innings before giving up another earned run in the fifth. He allowed four earned runs on five hits with four walks (two intentional) and two strikeouts in 3 2/3 innings.
In all, the Reds used six pitchers on Saturday.
To Mackanin, taking a loss when his starting pitcher made such a premature, unexpected exit isn't too difficult to handle. He said he hopes the Reds will be able to bounce back in Sunday's rubber match and win the fifth of their seven series since Mackanin joined the team on July 1.
"I feel positive about the way we've been playing," Mackanin said. "You don't normally win every game you play, and if this is one of the games in the series that we have to give 'em, because we had our ace on the staff and we had to remove him, I'd like to think that we're going to take tomorrow."