The Wolverines will be joined by North Cobb Christian and Mount Paran Christian in Region 6A, while Whitefield Academy will play in 9A this season.
It was a breakthrough season in 2010 for Walker (26-7), which lost to Aquinas 2-1 in the Class A state semifinals - the first final four appearance for the Wolverines since 2003.
Walker marched to the state semifinals in dominating fashion, averaging 10 runs a game.
The Wolverines lost a number of their key players from last year's squad, including pitchers Kannon Price and Stephen Moore, shortstop Art Sanguansri, catcher Ryan Wojciekowski, first baseman Kyle Henderson and outfielder Ryan Brush.
However, the cupboard is hardly bare for Walker, which entered the 2011 season ranked sixth in the preseason Class A state poll.
The Wolverines are 0-2 so far with losses to Class AAAA teams Sprayberry and Pope.
Walker a strong new core of seniors to lead the way, including infielder/pitcher Chris Ohmstede, catcher/second baseman Alec Diamond and outfielder Max Rones.
North Cobb Christian (12-12) will try to earn a return trip to the state playoffs after earning their first-ever GHSA bid in 2010, losing to Hebron Christian Academy 2-0 in the first round.
The Eagles lost a couple of their standouts from last year's team - second baseman Chas Collett and pitcher Eddie Denevillis, but they are boosted by the return of senior catcher Davis Richardson, senior pitcher Daniel Adams, senior shortstop Grant Hoover and junior outfielder Quintin Kitchen.
Mount Paran (10-15) lost a number of key senior players from last year, including outfielders Tyler Trenary and Tanner Jones, catcher Andrew Harrell, first baseman Matt Tenoschok and pitcher Kirby Alls.
As a result, the Eagles will feature a much younger lineup with several sophomores and freshmen.
Senior pitcher Zach DeBoy and senior shortstop Zack Greenwell will provide veteran leadership for the young Eagles.
Whitefield Academy (8-12) looks to contend for a state playoff berth in Region 9A with a team that returns many of its key players from last year.
The Wolfpack are off to a blazing start in 2011 with a 3-0 record and scoring an average of 10 runs a game.
Junior third baseman/pitcher Spencer Garrett, senior first baseman/pitcher Harrison Goudiss, senior pitcher Charles Warren and senior shortstop Brian Whitney will lead the way for Whitefield.