CHICAGO -- One of the things the Cubs learned from the disappointing 2011 season is their need for quality depth.

When they met in Mesa, Ariz., in February, the Cubs felt they were eight to nine deep as far as starting-pitching candidates. But just five days into the season, Andrew Cashner and Randy Wells were injured, and Chicago couldn't recover.

More injuries thinned the roster, as Geovany Soto, Marlon Byrd, Matt Garza, Kerry Wood, Darwin Barney and Carlos Zambrano all spent time on the disabled list. Every team has injuries, but the Cubs didn't fill the gaps.

The offense struggled to deliver when needed, and former manager Mike Quade had a tough time finding a lineup combination that worked. Quade remained optimistic but seemed to lose the players. He engaged in a shouting match with Ryan Dempster in the dugout in Pittsburgh in early July. Prior to a 10-game road trip in late July, Quade said the team could still contend.

"I'm not a lunatic," he said. "I understand there's a lot of work to do ahead of us. But we're playing the right clubs, and let's see if we can't put something together."

But the Cubs responded to that pep talk by losing to the Brewers, 3-2, on July 26 to end their first three-game win streak of the season.

They suffered deflating losses, dropping 44 games in which they had led, tied for second-most in the Majors with the Reds.

Year in Review
Looking back at 2011
2011 Cubs
Cubs 2011 stats
Final standings
Hot Stove tracker
MLB Year in Review

Another fifth-place finish prompted Cubs ownership to make major moves, including ousting both Quade and general manager Jim Hendry. New president of baseball operations Theo Epstein promises to build "a foundation for sustained success."

Here are five storylines from 2011.

1. Changing of the guard

On July 22, Cubs chairman Tom Ricketts told Hendry that he was being dismissed. But, in an unusual move, Hendry stayed one more month on the job to help through the Trade Deadline and sign Draft picks. It wasn't until Aug. 19 that he officially left his office.

"We didn't win enough games," Hendry said. "You don't win enough games, you can't fight change."

Ricketts made major changes once the season ended, signing Epstein to a five-year contract as president of baseball operations, then letting Epstein pluck his former Red Sox running mate Jed Hoyer to be general manager. The Cubs named another former Red Sox exec, Jason McLeod, to handle scouting and player development.

"I was ready for the next big challenge," Epstein said at his introductory news conference.

He vowed to build "a foundation of sustained success," which he said starts with a commitment to player development. Only time will tell whether Epstein & Co. can end the Cubs' 100-plus-year wait for a World Series title.

2. Carlos Zambrano

Hopefully, someone is keeping notes of Zambrano's roller-coaster life. It'll be an interesting book. In Spring Training, Zambrano said the time spent in anger-management therapy was beneficial. The goal for 2011, he said, was to stay healthy and do his job.

"I just want to focus on pitching and not talking," he said.

He was bumped from being the Opening Day starter, ending a streak of six consecutive years as the No. 1 pitcher. He had to come out of a start in April because of cramping in his hand, and in June, criticized closer Carlos Marmol after he gave up a game-tying RBI double to Ryan Theriot in the ninth en route to the Cardinals' 3-2 win over the Cubs. After the game, Zambrano blasted the team, saying players should be "embarrassed" and they were playing like a "Triple-A team." Said Zambrano: "We stink."

He went on the disabled list in early July because of a strained lower back, and in late July, returned and took a tough 2-0 loss to the Brewers. In his postgame session that day, Zambrano said the Cubs needed to make some changes, but wouldn't be specific. His frustration boiled over Aug. 12 in Atlanta. Zambrano served up five homers, then was ejected after throwing inside to Chipper Jones. He packed his gear and left Turner Field, telling teammates he was retiring. Zambrano was placed on the restricted list and did not pitch again.

Still under contract for 2012, Zambrano met with Theo Epstein in November and was told he had to earn his way back. Stay tuned.

3. Colvin, Cashner, Castro

The 2011 season was supposed to be the coming-out party for Tyler Colvin, Cashner and Starlin Castro. But Colvin, the No. 1 pick in 2006 who hit 20 homers in a promising 2010, struggled throughout the year and finished with a disappointing .150 average and more at-bats at Triple-A Iowa than anticipated. He was traded in early December to the Rockies along with DJ LeMahieu for third baseman Ian Stewart and a Minor League pitcher. Cashner, the No. 1 pick in '08, won a spot in the rotation but made one start, April 5, and then was sidelined most of the season because of a strained right rotator cuff. He was able to pitch in relief in September, and also in the Arizona Fall League.

Castro, who batted .300 his rookie season in 2010, showed no letdown offensively and led the National League in hits with 207. He was named to the All-Star team. But what was disappointing was his erratic defensive play -- he led the National League with 29 errors -- and the mental lapses. He was embarrassed during an ESPN broadcast when he was caught by TV cameras not paying attention to the game action. Quade benched the shortstop the next day.

"I'm real embarrassed," Castro said after the incident. "There's no excuse for that. That can't happen in a game. That will never happen again."

4. Quade

Quade was a great story. He was a local boy, having grown up in the Chicago suburbs, and he paid his dues as a coach and manager over 17 seasons in the Minor Leagues. He took over the Cubs for the final six weeks of 2010 when Lou Piniella retired and guided the team to a 24-13 record. Players backed him and "Q" got a two-year contract, starting in 2011. But the good vibe didn't continue. He had public disagreements with players, tied a club record for most ejections in a season (seven), finished with a 71-91 record and was dismissed on Nov. 2.

"You're disappointed, you're bitter, you're mad -- a million things," Quade said. "I woke up this morning, grabbed a fishing rod, had a cup of coffee and was managing the Cubs. Now you're not."

5. Ron Santo, Hall of Famer

Cubs players wore No. 10 patches on their uniforms in honor of Santo, the popular third baseman and radio analyst who died in December 2010. A bronze statue was unveiled at the corner of Addison and Sheffield outside Wrigley Field in his honor. One year after he passed, nearly on the exact date, Santo's family got the news he'd been waiting for. He was elected into the National Baseball Hall of Fame by the Golden Era Committee. Santo was one of 10 candidates on a ballot representing the era of the sport from 1947-72.

"To have this come after his passing, it just shows you can't give up," his wife, Vicki, said. "I'm a believer in what's meant to be. I believe he was meant to be in the Hall."

Santo had failed to make it into Cooperstown in his 15 years of eligibility on the Baseball Writers' Association of America ballot and also in numerous forms of the Veterans Committee. He needed a 75-percent vote, and received 15 of 16 votes cast. The news was greeted by joy and sadness. It's a shame Santo himself wasn't alive to celebrate.