When Ned Colletti took over as general manager of the Los Angeles Dodgers last November, he inherited a minor-league system bursting with talent. Prospect mavens Baseball America awarded the Dodger system’s collection of talent the top ranking in its annual Prospect Handbook, citing its depth and star power.But with most of their heralded youngsters having just completed High-A or Double-A levels in the minors, few expected significant big-league contributions from them in 2006.

Colletti also inherited a big-league team in disarray. Winners of 93 games and the NL West flag in 2004, the Dodgers collapsed to 71-91 last year. Injuries played a huge part; the Dodgers lost 1,357 player-games (third-highest in the majors), and 45% of their payroll (highest) to the disabled list. Seven players missed at least half the season, including closer Eric Gagne and outfielders Milton Bradley and J.D. Drew.

Acrimony between manager Jim Tracy and GM Paul DePodesta added insult to those injuries, and when the season ended, Tracy departed. Unhappy with DePodesta’s choice to replace Tracy, unpopular owner Frank McCourt fired the equally unpopular GM in late October, just as the winter’s real business was getting underway.

With several holes in the lineup to fill, Colletti could have been expected to trade some of the blue-chip prospects assembled by acclaimed scouting director Logan White for veterans; Dodger fans braced for the worst. But Colletti, who built a reputation as assistant GM for the rival Giants based around negotiation skills, opted for the free-agent route.

Rather than dole out expensive long-term contracts – as DePodesta had the previous winter with Drew (five years, $55 million) and pitcher Derek Lowe (four years, $36 million) – Colletti signed Nomar Garciaparra, Kenny Lofton, Bill Mueller, and Brett Tomko to one- or two-year deals, going longer only for Rafael Furcal, who signed a three-year pact. The only prospects Colletti traded were a pair of pitchers to Tampa Bay for Danys Baez, a proven closer who could provide insurance against Gagne’s elbow woes.

The moves were designed to keep the Dodgers competitive in a weak division without blocking key prospects or rushing them to the majors. But the best-laid plans of mice and GMs often go awry, and when the injury bug bit again this spring, the Dodgers turned to the kids.

In early May they recalled Andre Ethier (acquired from Oakland for the controversial Bradley) to man their decimated outfield and Russell Martin to fill in for injured catcher Dioner Navarro (who, at 22, was starting his first full season). Both quickly made impacts. Ethier homered in his second big-league game, and a day later Martin stroked an RBI double in his debut, setting off a streak in which the Dodgers won 16 of 18 with him catching.

A week after Ethier’s homer, a knee injury to Mueller forced the recall of Willy Aybar, who spent most of last season in Triple-A before hitting a torrid .326 AVG/.448 OBA/.453 SLG as a September call-up. This year, Aybar picked up where he left off, hitting safely in 20 of 21 games. By the end of May, the Dodgers promoted another outfielder, Matt Kemp; within a week of arriving, he’d homered in his first three games at Dodger Stadium, and through his first 18, had gone yard seven times.

The bullpen, where the once-elite Gagne has been sidelined again, has also been shored up by rookies. Gasthrowing, 288-pound Jonathan Broxton has become one of manager Grady Little’s key setup men, while 36-year old Japanese League veteran (technically a stateside rookie) Takashi Saito is now closing due to Baez’s struggles.

Even the rotation has gotten a shot in the arm, with Chad Billingsley, considered the system’s crown jewel, debuting on June 15 with a 5.1-inning start in which he he allowed two runs while dazzling the Padres with a 96 mph fastball and a curve thrown for strikes when behind in the count.

The rookies are a big reason why the Dodgers are even contending in the NL West. Collectively, only the surging Marlins – amid a fire sale-induced youth movement that’s seen as many as seven rookies playing at once – have gotten more production out of their freshman class. According to Baseball Prospectus’s Value Over Replacement Player (VORP) metric – which measures a player’s offensive or pitching contribution in runs relative to that of a freely available minor-leaguer or benchwarmer – Marlins rookies have accounted for a collective VORP of 106.4 runs, split about evenly between pitchers (57.3) and hitters (49.1). Dodger rookies have totaled 51.0 VORP (33.2 for hitters, 17.8 for pitchers), albeit in considerably fewer plate appearances and innings; only four other teams have topped 30.

With the rookies quickly finding their comfort zone, Little has followed suit. Martin has performed so well that the manager refuses to guarantee Navarro will regain his starting job. Regarding Kemp, Little admits, “It’s hard for me to write a lineup without his name in there,” which has cost Ethier considerable playing time lately. Such a numbers game has already claimed Aybar, who was sent down to Las Vegas on Tuesday to make room for Cesar Izturis, formerly the team’s regular shortstop but now trying out for a utility role as a prelude to a mid-summer swap.

The trade market may further affect the fates of these rookies. The Dodgers, squarely in contention, are likely to deal for veteran insurance, and they may part with youngsters who’ve helped them get there while elevating their own stock.

Such depth creates nice problems to have. The system’s formidable stock of talent insures that whether or not they win the West this year, blue skies are here again for the Dodgers.

Mr. Jaffe is a writer for Baseball Prospectus. For more state-of-the-art analysis, visit www.baseballprospectus.com.