ATLANTA — Bobby Cox has been through this before.

Tom Glavine left. So did Greg Maddux and Andruw Jones.

Still, the longtime Atlanta manager sounded as though he took a shot to the gut when John Smoltz called this week to deliver the stunning news: He was signing with the Boston Red Sox after 21 years with the Braves.

"He said, ‘I appreciate pitching for you.’ I was like, ‘John, holy cow, what are you doing here?"’ Cox said Friday, remembering his call from Smoltz earlier in the week. "It really hit me then. You hate giving up one of your best guys. He’ll be a Hall of Famer for sure."

The 41-year-old Smoltz had spent his entire big league career with the Braves, but that run came to an end when he agreed this week to a $5.5 million, one-year contract that could be worth another $5 million in bonuses based largely on how much time he spends on Boston’s active roster.

The Braves weren’t willing to guarantee that kind of money to an aging pitcher coming off major shoulder surgery, which led to a departure with bitter overtones — not unlike Glavine’s decision to sign with the New York Mets in 2002 after 16 seasons in Atlanta.

General manager Frank Wren defended his negotiations with Smoltz, saying the team made an offer that would have been worth a similar amount if the right-hander was healthy enough to pitch.

But the Braves weren’t willing to offer nearly as much guaranteed money — their proposal was for $2 million — and the bar to reach some $8 million in possible incentives was much higher than Boston’s proposal. Smoltz went so far as to issue a statement saying "there were large discrepancies between the offer from the Braves and offers from other teams."

"We were all surprised. We had hoped John would remain a Brave," Wren said. "But as we approached this offseason, we made it very clear to everyone that we did not want the same thing to happen to us that happened to us last year. We had to focus on rebuilding the pitching staff with players who had some certainty of being able to start the season healthy for us."

Atlanta’s starting staff was ravaged by injuries in 2008, with Smoltz, Glavine and Tim Hudson all undergoing season-ending operations. The bullpen wasn’t exempt from the injury woes, either — closer Rafael Soriano and setup man Peter Moylan also went down for the count.

Not surprisingly, the Braves missed the playoffs for the third season in a row with a 72-90 record that was their worst since 1990, the year before they started an unprecedented streak of 14 straight division titles.

Smoltz has started throwing off the mound, but it’s highly unlikely he’ll be ready to go on opening day — less than a year removed from surgery to repair his labrum, AC joint and biceps. Wren said the Braves couldn’t afford to divert a major chunk of their budget to someone with a questionable outlook.

"Even by John’s own admission, he’s not going to be ready until sometime around midseason," the GM said. "With that being the case, we needed to build our staff based on starting the season in April. That’s always been our plan, always been our focus."

The Braves are looking at Glavine the same way. The left-hander, who will be 43 by opening day, hopes to pitch another season but the team is taking a wait-and-see approach.

Glavine, coming off elbow surgery and not as far along in his rehab as Smoltz, hopes to be cleared to throw off the mound before the month is out. Only then will the Braves be willing to discuss a possible contract.

"We have been very up front with both players all along the way," Wren insisted.

Having already spent five seasons in New York, Glavine has no plans to leave again. The 300-game winner says he’ll retire if he’s not pitching for Atlanta.

Smoltz approached negotiations with a decidedly different mindset. He obviously felt the Braves were trying to take advantage of him with a low-ball offer, believing he would never actually leave the only big league team he’s ever played for. He decided to call the bluff, if that’s what it was.

Wren declined to go into specifics about the negotiations, but did say, "It’s unfortunate. We all wanted to keep John Smoltz, and we made a very strong offer to do that. It’s one of those things where John made the decision to go to Boston. We can’t control that."

So the Braves are moving on.

Already rejected by Smoltz and A.J. Burnett, and having failed to complete a trade for San Diego ace Jake Peavy, they turned their attention to free agent Derek Lowe, a 14-game winner for the Dodgers last season. He was in Atlanta to meet with team officials on Thursday.

"I would love to have Derek Lowe," Cox said. "He would make a big difference for us."

While some Braves players — most notably, third baseman Chipper Jones — questioned the team’s commitment to winning after Smoltz got away, Cox is used to seeing new faces in the clubhouse. He’s also convinced that Wren will bolster the roster before the team reports to spring training next month.

As it stands now, Jair Jurrjens and newcomer Javier Vazquez are the only healthy pitchers who won as many as 10 games last season. Hudson isn’t likely to be ready until after the All-Star break.

Also, the team could use at least one more power-hitting outfielder to juice up the offense.

"It’ll all work out. It always does," said Cox, the Braves’ manager since 1990. "We’re still trying to put a club together. We’re going to do some things."