"It's that time of year," Sveum said Friday. "That's why I kept my phone on high volume today. Obviously, you never know what could happen like that. One phone call changes the whole scenario. It can happen quick. It can happen with more than one guy."
Dempster (5-3, 1.86 ERA) was reportedly being sought by several teams, including the Dodgers, who have made an offer for the right-hander.
According to MLB.com's Ken Gurnick, the Dodgers will not get into a bidding war because they also need to add offense, preferably a corner infielder, even more than they need Dempster. The Dodgers' farm system also is a little thin in the kind of prospects needed to land All-Star caliber players like Dempster, the Padres' Chase Headley, or the Phillies' Shane Victorino. Theo Epstein, Cubs president of baseball operations, has made it clear they're looking to improve on pitching in the organization, although they wouldn't reject a potential high-impact position player.
The Cubs were prepared just in case a deal was made. Casey Coleman was scratched from his start Thursday for Triple-A Iowa, but a team official said that was done in case newly acquired pitcher Justin Germano could not get to St. Louis. The Cubs acquired Germano from the Red Sox late Thursday for cash considerations, and he did arrive at Busch Stadium in plenty of time for the game, as well as a brief throwing session.
"You have to prepare for stuff like this," Sveum said about losing a starting pitcher. "It's never a perfect world because you never know that day or that hour when it's going to happen."
Sveum was more than happy to have Dempster on the mound. This season has been the right-hander's best, despite two stints on the disabled list, and he currently leads the Major Leagues with a 1.86 ERA. He missed time from April 21-May 3 because of a right quad strain, and was sidelined June 18-July 8 because of right lat tightness.
His record would be better if he had received more run support early in the season. Dempster went 18 starts, dating back to August 2011, without a win until June 5 when he beat the Brewers. He has 10 quality starts out of his 14 this season.
Dempster has won his last five starts without giving up a run, and his 33-inning scoreless streak is the longest by a Cubs pitcher since Ken Holtzman's 33-inning streak in 1969.
"Whether it pans out or not, the more starts for us, the better," Sveum said.
Dempster, 35, would be a pure rental for any team, which most likely is effecting the negotiations. He is in the last year of his four-year contract with the Cubs, which is paying him $14 million this season. Players must be with a team for an entire season in order to qualify for Draft-pick compensation, according to the new CBA.
Dempster has played 10 years in the Major Leagues and five with the Cubs, so he has the right to veto any deal. However, the right-hander was expected to approve of a trade to the Dodgers, where he would be reunited with his friend, Ted Lilly.
Epstein has kept Dempster up to date.
"It's just kind of like, 'Hey, there's teams interested,' and that's great," Dempster said Thursday. "Nothing imminent, not that I know of. I'm sure if they have something, they'll come to me. But right now, I'm just trying to get ready for [Friday's] game."
The Tigers, Braves and Nationals also were believed to be pursuing Dempster as well.
Was it a risk for Demspter to start Friday?
"I don't really think about that," Sveum said. "He is what he is, and after a tough outing or not, he's still one of the best pitchers, if not by earned-run average, the best pitcher in baseball."
He's also one of the most popular players in the Cubs clubhouse. Dempster signed with the Cubs in January 2004 after undergoing Tommy John surgery in August '03. He was the Cubs closer for three seasons, starting in 2005, and is one of 17 pitchers with at least 100 wins and 85 saves. He returned to the rotation in '08, and went 17-6 with a 2.96 ERA. He's finished in double-digit wins in each of the last four seasons.
"You can't deny it wouldn't help the clubhouse -- it would only take away from the clubhouse atmosphere, the leadership role he has," Sveum said. "You don't replace the whole package like he has."
Dempster doesn't overpower hitters, but has overmatched them with his precise command this year.
"He's like a five- or six-pitch pitcher, even though on the resume it's four pitches," Sveum said. "When you can move your fastball up and down on purpose, it's like having another pitch."
The Trade Deadline is July 31. Sveum is trying to prepare for Dempster's possible exit.
"The reality of losing pieces of something that's working really well is not easy to swallow for a team, but that's the way it is sometimes," he said.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.