In the natural world, a keystone species plays a critical role in maintaining an ecosystem. Remove the individual and the whole suffers as a result.

In the world of baseball, the second baseman is the keystone species, of course, and to paraphrase Hall of Fame manager Casey Stengel: If you don't have one, then you're not going to turn many double plays.

The Mariners are just one organization attempting to stretch ecological tendencies this spring as they introduce a few of their players to the keystone. Foremost among those players is Dustin Ackley, the second overall pick a year ago as a first baseman from North Carolina. Seattle challenged the 22-year-old with an assignment to Double-A West Tenn this season, where he's off to a 2-for-22 start.

Ackley also has committed two errors through his first five games, but that's just part of the process, according to Mariners farm director Pedro Grifol. "Every day he goes through something he's never done before. It won't come overnight," he said. "He says he's comfortable turning double plays, but every day something new comes up—a runner bearing down, the triangle that forms with the center fielder and shortstop on pop-ups, over-thrown relay throws."

Further down the organizational ladder, the Mariners are employing a job-share situation with low Class A Clinton, where a pair of natural shortstops will divvy up middle infield responsibilities. Nick Franklin, a first-round selection (27th overall) from Altamonte Springs, Fla., last year, will share the shortstop position with 19-year-old Venezuelan Gabriel Noriega, whose defensive acumen netted him $800,000 on the international market three years ago.

A switch-hitter, Franklin homered from both sides of the plate in Saturday's game against Peoria. He went 4-for-4 in the game, while also hitting a double and a triple, good for 13 total bases in all.

Seattle's middle-infield logjam reminds Grifol of the 2004 season, when the organization had Asdrubal Cabrera, Yung-Chi Chen and Oswaldo Navarro with short-season Everett.

"In this case, both (Franklin and Noriega) have a chance to end up as true major league shortstops," Grifol said. "But the way we look at it, learning multiple positions can only help a player—you know, just in case. It's like what we've done with (Matt) Tuiasosopo, who plays all over the infield now."

Mario Martinez (third base) and Dennis Raben (first) round out Clinton's all-prospect infield, with supplemental first-rounder Steve Baron behind the plate. Raben, a second-round pick from Miami in 2008, missed all of last season while recovering from microfracture knee surgery.

Other prospects learning second base on the job . . .

• The Padres' Logan Forsythe hit his way to Double-A last year in his full-season debut. For an encore, the natural third baseman is trying his hand at second, a position he hasn't played since his days at Arkansas. He was off to a fine start with Double-A San Antonio, going 8-for-19 (.421) with a double, a homer and five walks. By shifting Forsythe, the Padres have increased his versatility while also making room at third base for James Darnell. Slugging first baseman Matt Clark, who drove in 101 runs last season, and shortstop Beamer Weems, a defensive whiz, round out the Missions' infield.

• The Padres drafted but did not sign fourth-round pick Jason Kipnis as a draft-eligible sophomore in 2008. Cleveland had better luck last year, inking the Arizona State outfielder out of the second round. Kipnis began playing second base in instructional league last fall and has generated positive reviews thus far for his play with high Class A Kinston. He was off to a 6-for-16 (.400) start with a home run.

• Mets' 2008 first-rounder Reese Havens played shortstop for three years at South Carolina, but evaluators agreed that his pro position most likely would be second base. He began that transition in the Arizona Fall League last year, playing six of his 10 games at the keystone. He batted .368 in 38 at-bats, showing his trademark patience (eight walks) and power (six extra-base hits, including two homers). Havens has yet to suit up for Double-A Binghamton, but he's working on defensive drills in extended spring training as he recovers from an oblique strain. The Mets prefer to be a bit cautious with him after all the time missed last season with nagging injuries.

DISH PIECES

• In less-positive Mariners news, righthanded reliever Ricky Orta had Tommy John surgery this spring. He enjoyed a breakthrough with Double-A West Tenn last season, striking out 41 in 42 innings and holding batters to a .196 average in his first pass as a full-time reliever. Orta then went on to dominate the Arizona Fall League and earn his spot on the 40-man roster. He made three trips to the disabled list in 2009 with blister problems and elbow soreness. Orta's injury, coupled with the trades of Phillippe Aumont and J.C. Ramirez (for Cliff Lee), has thinned the organization's relief corps since our Prospect Handbook went to press last December.

• Marlins' first baseman Logan Morrison enjoyed his first taste of Albuquerque last night, going 3-for-5 with his first double, triple and home run of the young season. The lefthanded hitter plays for Triple-A New Orleans.

• We may need to come up with snappy nickname for the low Class A Cedar Rapids pitching staff, which to this point has allowed just nine earned runs in 44 innings (1.84 ERA) of Midwest League play. The prospect-fortified rotation features power righthanders Garrett Richards (5 IP, 2 H, 0 R, 7 SO, 0 BB) and Fabio Martinez (5 IP, 2 H, 0 R, 11 SO, 3 BB) as well as lefthander Pat Corbin (6 IP, 5 H, 1 R, 2 SO, 3 BB). Angels supplemental first-round lefty Tyler Skaggs made his season debut for the Kernels last night, allowing only one run in five innings while striking out three and walking three.

• Veteran minor league third baseman Mike Hessman connected for two home runs over the weekend, upping his career total to 313, more than any active player. The 15-year veteran, who plays for the Mets' Triple-A Buffalo affiliate, also has hit another 13 bombs in the big leagues. According to a Bisons press release, the active leaders for minor league home runs—excluding Kit Pellow, who hasn't played affiliated ball since 2005 but was active through last season in the Mexican League:

NPB stands for Nippon Professional Baseball, which encompasses Japan's two major leagues. McClain currently resides on the disabled list, but with 17 home runs this season, the 37-year-old will reach 400 for his professional career. With another huge year, Branyan could join him. He's 34 years old and needs 26 bombs to reach 400.

While inputting minor league rosters for our issue is mostly mind-numbing work, it can provide insight as to the identity of fast-risers in an organization. Check back later for a sampling of such players from "my" four org: the Angels, Mariners, Mets and Padres.