San Francisco is in the market for a head coach once again with Jim Tomsula being fired after just one season. FOX Sports Senior NFL Writer Alex Marvez looks at three replacement candidates who either should or could be on the 49ers' radar.

Kyle Shanahan

The 49ers interviewed Mike Shanahan about replacing Jim Harbaugh in the 2015 offseason. While the 63-year-old Shanahan has long-standing ties to the franchise -- having served as San Francisco's offensive coordinator for the 1994 squad that won Super Bowl XXIX -- Mike's son may be a more viable and better long-term option even though he would become the league's youngest head coach at age 36.

More from FoxSports

Kyle Shanahan already has spent eight years as an offensive coordinator and helped wide receiver Julio Jones and running back Devonta Freeman post career-best numbers in Atlanta this season. Fixing the NFL's lowest-scoring offense is an obvious priority for San Francisco heading into the 2016 campaign.

Eric Mangini

He would join Tomsula as the second straight head coaching hire from the current coaching staff. Although this wouldn't appease 49ers fans seeking more wholesale change, San Francisco probably wouldn't have taken such a tumble in 2015 had the more experienced Mangini gotten the nod ahead of the overmatched Tomsula.

Mangini has spent time coaching on offense and defense since joining the 49ers staff in 2013, which gives him first-hand perspective on what needs fixing. Five years removed from his last head coaching opportunity, Mangini also may have learned from the mistakes that doomed his prior stints with the New York Jets and Cleveland.

Chip Kelly

FOX Sports NFL Insider Jay Glazer reported Sunday that the 49ers would be considering some big-name candidates. Kelly certainly fits the bill although whether he could co-exist with general manager Trent Baalke as far as personnel power is part of the decision-making process for 49ers owner Jed York. Kelly's arrival could breathe new life into quarterback Colin Kaepernick, whose skill set would fit a zone-read style of offense.