Having just shambled through their third consecutive losing season—and the 10th in the last 11 years in which they failed to make the playoffs—the Mets would seem limited in the measures they can take this offseason to reshape their roster.

They handed contracts to Jason Bay and Johan Santana that were so expensive that their cost makes it all but impossible for the Mets to trade either player. They might decide to trade third baseman David Wright or let shortstop Jose Reyes sign elsewhere, but either move would probably signal a rebuilding phase for the franchise. And with their payroll set to drop to about $110 million from about $140 million, general manager Sandy Alderson won't be able to go on a major winter spending spree.

Former Nationals manager Jim Riggleman, above, is a candidate for a Mets coaching position. Associated Press

What the Mets can do, though, is overhaul their coaching staff. They did it last year when they said goodbye to manager Jerry Manuel and hired Terry Collins to replace him. And they did it again this year when third-base coach Chip Hale departed for Oakland and the Mets fired bench coach Ken Oberkfell, first-base coach Mookie Wilson and bullpen coach Jon Debus. They've since promoted Tim Teufel (who will replace Wilson) and Ricky Bones (who will replace Debus) from their minor-league organization to Collins's staff.

So how much difference can a few new coaches really make for the Mets? At one level, the question seems silly: Unless the coaches themselves can launch a baseball over Citi Field's imposing fences or strike out Chipper Jones in the clutch, what effect can they have? "A quality coaching staff can have a major impact," Alderson said Tuesday.

As an example, Alderson cited Dave Hudgens, the team's hitting coach. In 2011, Hudgens's first season with them, the Mets led the National League in walks and were second in batting average and on-base percentage. They were collectively more patient at the plate—a result, Alderson said, of Hudgens's influence.

Hudgens, then, used his technical expertise to help the Mets' hitters—one of three ways that a manager or coach can effect improvement, according to Benson Rosen, a professor of organizational behavior at the University of North Carolina-Chapel Hill. The other two are a bit less defined: interpersonal and leadership skills. Those factors would seem the province of Collins and his next bench coach, whoever that may turn out to be.

While a baseball team's hitting and pitching coaches must be authorities in their respective areas of concentration, a bench or infield coach might have a more nebulous role. Is he in charge of the team's defensive or baserunning fundamentals? Is he an adviser to the manager? It depends.

"He can make a world of difference," said MLB Network analyst Billy Ripken, whose father, Cal Ripken Sr., was a coach and manager with the Orioles from 1976 to 1992. "He can set a dynamic culture where performance can be enhanced."

The changes to Collins's staff fit a pattern common among professional sports franchises when it comes to hiring managers and coaches: If the approach you just tried failed, try its opposite next. The most revealing symbol of Manuel's tenure—aside from his own tranquil, detached personality—was the daily clubhouse card games that first-base coach Razor Shines would play with a few of the Mets' regulars. When the edgy, intense Collins came on to manage a team full of young players, his coterie featured two members (Oberkfell and Wilson) who had never been bench coaches in the majors before.

Now, according to Alderson, major-league coaching experience will be a "strong consideration" for the Mets in filling the staff's two remaining vacant positions—which explains why they are interviewing former Nationals manager Jim Riggleman Wednesday. The Mets will also interview former Athletics manager Bob Geren, according to a person familiar with their plans. "We want guys who have done it before," Collins said.

—Brian Costa contributed to this article.

Corrections & Amplifications
An earlier version of this article incorrectly said Ken Oberkfell and Mookie Wilson hadn't previously coached in the majors. Oberkfell had been the first-base coach in 2008, and Wilson had been the team's first-base coach from 1996-2002.

Write to Mike Sielski at mike.sielski@wsj.com