The Nationals are finalizing a coaching staff that will have only one significant change.

Pat Corrales, 70, is stepping away from the bench coach’s job, which will be filled by a younger coach who could potentially replace Davey Johnson as the Nationals’ long-term manager after the 2012 or 2013 season. One strong candidate to take over as bench coach is Class AAA Manager Randy Knorr, who has been with the organization as a player, coach or minor league manager since 2001.

Knorr spent September with the Nationals, sitting next to Johnson and offering background on the myriad young players he had managed in the minors. Knorr has managed at several levels of the Nationals’ minor league system and has grown familiar with every homegrown player the team has produced.

General Manager Mike Rizzo also has great respect for third base coach Bo Porter, who has interviewed for managerial positions several times in the past, including with Rizzo and the Nationals. If Porter does not become another team’s manager before Johnson leaves his current role, he would be a prime candidate to replace him, too.

Porter will continue to coach third base this season, though. Team officials feel he makes excellent decisions at third base and that placing him on the bench would waste that skill.

Corrales, a trusted evaluator, will be able to return to a position in player development. He became the Nationals’ bench coach in midseason, after Jim Riggleman resigned and John McLaren was reassigned.