The Lions announced Thursday they were promoting Jim Colletto to offensive coordinator in Martz's place.
"I wish it would have been different, but at the end of the day, these are decisions coaches and management need to make, and as players, we need to just do our job," Kitna told The Associated Press on Thursday night. "I'm not sure what to expect because I've been immersed in coach Martz's system, so I'm not sure what Colletto's philosophies are.
"I'm just going to do the best I can to help make it work."
Kitna was outspoken late in the season in Martz's defense as speculation grew that he'd be fired. The Lions opened the season 6-2, then lost six in a row before finishing at 7-9.
Colletto was Detroit's offensive line coach in 2007.
"Jim is an excellent football coach," Marinelli said Thursday in a statement. "He knows what it takes to win in this league and I am confident that he will do a tremendous job leading our offense.
"His appointment also allows us to maintain continuity in our offense, which is important to our players."
"I'm looking forward to playing in his offense," offensive tackle Jeff Backus wrote Thursday in a text message to the AP.
Marinelli also promoted Kippy Brown to assistant head coach and passing game coordinator and Shawn Jefferson to wide receivers coach. Fred Reed, a defensive assistant the past two years, will not return next season.
Martz, who had one year left on his contract worth a reported $2 million, led Detroit's offense the past two seasons.
Colletto has 41 years of coaching experience, including eight seasons as an NFL offensive line coach and as a head coach at Purdue and at Cal-State Fullerton.
"The running backs worked together with him closely in 9-on-7 drills," said Lions running back T.J. Duckett, a free agent who wants to return. "You could tell he's real in-tune with all the schemes, both running and passing."
Brown is entering his third season in Detroit and 16th in the NFL, including stints with Houston, Green Bay, Miami, Tampa Bay and the New York Jets.
Jefferson, a former standout receiver in the league, has been an assistant in Detroit the past three seasons.
Copyright 2007 by The Associated Press