But practically overnight, Cotts was sent to the minors for the first time since 2003, a year in which he went straight to the majors from Double-A.
This season, Cotts went straight from a zero ERA to a 4.86 mark in a span of just four games, thus resulting in the trip back to the minor leagues.
The difference between success and failure on the pitcher's mound is as fine a line as it ever has been, says Cubs Assistant General Manager Randy Bush, and Cotts has learned that lesson the hard way this season.
"The stuff is just as good as it was when he was on a World Championship team and had a (1.94) ERA. The stuff is still there," said Bush.
But "stuff" alone doesn't always equal success.
"What's happened now is he's not commanding his stuff as well," Bush said. "When you have good stuff and you're behind in the count, you throw it down the middle and it gets hit hard in the big leagues. He's trying to get back to having that command, and he will get back to that."
Cotts had never thrown a pitch in Triple-A until this year. Having established himself as one of the best setup men in the White Sox bullpen just two short years ago, he might have figured that the only time he would experience life in the minor leagues again would be on a rehab assignment.
In fairness, Cotts has been injured this season. But that has had nothing to do with his struggles, which existed well before he sustained a hamstring injury and spent a month on the shelf beginning in mid-June.
"Starting and not doing well is what affected my numbers," says Cotts, 0-1 with a 7.33 ERA in six starts with Iowa earlier this season.
Cotts said he was not upset by the Cubs' decision to send him down despite his success in the first month followed by a pair of bad outings.
"It really came down to a matter of numbers," Cotts recalled. "It might have been a little shocker, but you have to deal with it."
Cotts' goal now is to get back to the level he was once dominant at.
"That's the whole goal for all of these guys," Iowa pitching coach Mike Harkey said of Cotts. "For Neal, who's already had a lot of success at the major league level, he needs to understand ... he does understand that his fastball command is something that has to be better.
"He's worked hard to make it better, to sharpen up his breaking stuff and to become a better pitcher. It's been tough for him, but he's been as positive as any pitcher that's in the situation that he's in," Harkey added.
While Cotts made several starts earlier in the year with Iowa, the left-hander has since gone back into the bullpen after coming off the disabled list. (He was originally a starter in the White Sox and Oakland A's systems.)
Last Thursday night, the southpaw tossed a season-high 3 2/3 innings from the bullpen in Triple-A Iowa's 10-2 victory over the New Orleans Zephyrs. He scattered one run on two hits, striking out four without allowing a walk.
The win was Cotts' first since July 1, 2006, in a game at Wrigley Field. He said afterward that he still wasn't sure what role he may fill in the long-run, but the safe money for now is on the bullpen.
"It's hard to tell," Cotts said when asked about his role with the Cubs. "I've done both and I feel comfortable doing both. Coming out of the ‘pen now, it feels more comfortable since I've done it for the past three years."
Regardless of what role he's in, Cotts will need to show the Cubs the same kind of consistency and command that he showed for the White Sox in 2005 if he is to carry his success from that year over to the other side of town.
He may get his chance when big league rosters expand next month.
"He's got a good arm, but as with the majority of our pitchers, there are times when they have big league outings and there are times where they don't," Iowa manager Buddy Bailey said of Cotts, who has struck out 42 batters and walked 28 in 44 2/3 innings with Iowa overall this season.
"That's all it is for him – getting back to commanding his pitches and having that success to where he knows he can throw a pitch in a certain count to get guys out," he said.
For now, Cotts appears to be biding his time at Triple-A, where his numbers have been considerably stronger since returning to the bullpen.
He has a 3.38 ERA and a .189 average against in 15 relief outings. Those numbers, duplicated at the major league level, would look good in a bullpen that has at times this season been no less inconsistent than Cotts.
His teammates have enjoyed the veteran experience Cotts brings to a clubhouse that is made up of many young pitching prospects.
"He knows how to take care of his business and he shows us every day what it's like to be a professional," said Iowa reliever Clay Rapada. "He's been up there for a few years so it helps when he's working hard because it shows the rest of us how hard we need to work just to get there."