The deal was not completed until Hart had finished his start on Thursday, picking up the win in the Cubs' 12-3 romp over the Houston Astros. The right-hander gave up three runs on six hits over six innings, then got the news.
"It's definitely a first for me," Hart said. "They didn't tell me in the third [inning], and I'm glad about that. They waited. I'm not sure what they knew."
Cubs general manager Jim Hendry said he had been in talks for a long time with Pirates GM Neal Huntington about Grabow. Marshall was the only left-hander in the Cubs' pen, and has a 1.25 ERA in 29 games in relief. During the Cubs' recent series in Philadelphia, he joked with former Chicago pitcher Scott Eyre that he could use some help. Now, he's got it.
"When he's in trouble, he has a good knack of getting out of trouble," Hendry said of Grabow. "He's pitched in eighth and ninth innings now for a few years. We thought it was a good complement for Marshall."
Hendry said they were concerned that Marshall would get worn out down the stretch, especially if he has to get warmed up, then sit.
"To get another lefty of that caliber, I think, is essential," Hendry said.
Grabow, 30, had a 3.42 ERA in 45 games for the Pirates, including 16 holds. Right-handers were batting .234 against him, while lefties were hitting .275. He was to join the Cubs in Florida on Friday.
"It gives us options as a lefty, and a pretty good one," Cubs closer Kevin Gregg said of Grabow. "He's been around, he knows how to pitch late in games with the game on the line. It'll be good for Sean to be able to take a breather every now and then. It seems like he's been pitching every day. It'll be nice to use each other to get some rest."
Gorzelanny, a native of Evergreen Park, Ill., was pitching at Triple-A Indianapolis, where he was 4-3 with a 2.48 ERA in 15 starts. In his latest outing Monday, he gave up two runs on seven hits over 6 2/3 innings and struck out six. He was with the big league team from mid May to early June.
"Pitching, you can't say enough about it," Gregg said. "The good teams have pitching. If he comes up and pitches the way he can, he'll definitely help us."
For now, Gorzelanny will be assigned to the Cubs' Triple-A Iowa roster. He could fill the rotation spot vacated by Hart, who was filling in for Ted Lilly, on the disabled list with inflammation in his shoulder. Cubs manager Lou Piniella and pitching coach Larry Rothschild could figure out the rotation on the plane ride to Miami on Thursday.
Former Pirates general manager Dave Littlefield, now a special assistant to Hendry, had scouted Gorzelanny in the Minors. The lefty won 14 games in 2007, his first full season in the Majors. When Hendry talked to the left-hander, he said, "Gorzelanny seemed like the happiest guy on the planet."
"We've always liked him," Hendry said. "Dave Littlefield feels he's back on the path to where he was."
Apparently, Huntington has been interested in acquiring Hart for some time, but the Cubs needed more than Grabow to make the deal.
"When Teddy went down," Hendry said, "Hart couldn't go in any deal unless we were getting more than another reliever."
The Cubs have had to deal with a string of injuries, most recently losing Lilly and outfielder Reed Johnson (fractured foot). So far, they've filled in internally, but they don't have any left-handed pitching options in the Minor Leagues. They did sign B.J. Ryan after he was released by the Toronto Blue Jays, and he was to make his second outing for Triple-A Iowa on Thursday night.
"It's way too early to tell when or if [Ryan] will be ready to help us in the near future," Hendry said.
It was an emotional day for Hart, who was congratulated for the win, then had to say goodbye as his teammates headed for the bus.
"It's one of those things where you never want to get traded, especially from a team that's in first place and a team that's playing so well," Hart said. "A lot of these guys I came up with. I've been through it before and that helps a little bit. It's a great opportunity for me in Pittsburgh. Hopefully, I'll be pitching here in a couple weeks."
Mark the calendar, Hart fans. The Pirates play the Cubs at Wrigley Field Aug. 14-16.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.