Leading candidates from inside the organization:
1) Bench coach Don Wakamatsu. He gained some limited managerial experience during the 2006 season when Showalter was hospitalized and during his supsension. He also has a strong relationship with GM Daniels and the Rangers organization and players.
2) Hitting coach Rudy Jaramillo.
3) Former farm director Trey Hillman. He was also a managerial possibility 4 years ago before the hiring of Buck Showalter.
Leading candidates from outside the organization (in no certain order):
1) Angels pitching coach Bud Black.
2) Athletics 3rd base coach Ron Washington.
3) Recently fired Marlins manager Joe Girardi.
They do not appear to have interest in Dusty Baker or Lou Piniella. I don't know that much about Piniella as a manager or how he connects with the players, but I am personally happy that the Rangers are not interested in Baker. Especially with some hot young prospect pitchers coming up.
Two other highly unlikely candidates, but candidates nonetheless, are former Twins manager Tom Kelly and former Blue Jays manager Cito Gaston.
So far Wakamatsu is the leading candidate and is expected to be a very tough candidate to beat out for the job.