PHILADELPHIA -- Roy Oswalt packed up his things, shook a few hands, and left the Phillies' clubhouse late Friday night at Citizens Bank Park.

It might have been his last time there.

Those thoughts certainly had to cross the minds of Jimmy Rollins, Ryan Madson, Raul Ibanez, Brad Lidge and others following Philadelphia's 1-0 loss to the St. Louis Cardinals in Game 5 of the National League Division Series. The Phillies finished the regular season as the best team in baseball, with a franchise-record 102 victories, but they failed to advance to the NL Championship Series for the first time since 2007.

Personnel changes follow every season, and this offseason will be no different.

Some of those potential free agents, maybe all of them, will not be back.

"I don't think management is going to give up on everything because of what happened here," Cliff Lee said in a quiet clubhouse. "We've still got a lot of guys coming back in this group. We're still going to have good pitching. We're still going to be a good team. It's not my decision who they sign and what they do and the moves they make. I don't see them giving up, though. So I expect to come in here next year and make another run at it."

But can the Phillies repeat their regular-season success next season and beyond, and can they do more with it? This was the best of the Phils teams that have won the NL League East title the last five years in a row, but they couldn't return to the World Series.

"It's tough," Cole Hamels said. "Just because you have to have the right guys, and they have to be at their peak or hot zone. The core guys we have, you want to keep them as long as you can, because that's kind of what the organization built a team around. You don't want to see those core guys exit without something to really show. And the past couple years, we haven't had anything to show. That's kind of up in the air, I think."

The Phillies outscored the Cardinals, 21-19, in the series, but 11 of those runs came in Game 1. They hit .181 with nearly as many strikeouts (22) as hits (23) in the final four games of the series. Those numbers are especially frustrating because a lackluster offense doomed Philadelphia in last year's NLCS against the San Francisco Giants.

Fans have been criticizing the Phillies' offense for its performance in the final four games, but Lee blew a 4-0 lead in Game 2. Oswalt allowed five runs in six innings in Game 4.

"I take a lot of responsibility," Lee said. "I had a four-run lead and wasn't able to keep it. If I was able to do that, we would have swept. I feel a lot of responsibility. I think it's all of us, though. Each of us can look back at what we could have done to prevent it."

Rollins, Madson and Ibanez will have other things to consider as free agents. The Phillies have a club option on Lidge, which is a long shot to be exercised. Oswalt also has a mutual option, which seems unlikely to be exercised.

Changes are coming. An opportunity was wasted. There will be a next year, but there are no guarantees.

"I'll be right back here," Roy Halladay said. "Honestly, I don't care where you go, there is no team where you're guaranteed to win anything. We have an unbelievable team here. Winning the World Series is always going to be the goal, but when I came over here, I didn't think it was going to be easy. I knew it was going to be hard. I knew it is not something you do every year. I really enjoy the process of going after it, playing the games and getting to this point in the season. Hopefully, we get to the point where we get some things going our way and we come back here and do it again."