Though born in Wisconsin, Eigner grew up in Minnesota and was a standout player for Rosemount, topping two points per game in his final two years with the Fighting Irish. Despite his scoring numbers, Eigher played two seasons in the USHL after graduating before he got his first taste of college hockey. Eigner played sparingly in his first few seasons with Bowling Green under Jerry York but he grew into a leadership role with the team and served as captain for the 1992–93 campaign. After Bowling Green, Eigner signed with the Fort Worth Fire and had a good season while the Fire finished last in the league. Eigner moved up to the ECHL the following year but after poor results he found himself back in the Central Hockey League and finished his playing career with the Tulsa Oilers. in 1996 Eigner returned to Minneaota to coach at his old high school, earning the Section 5AA Coach of the Year award in his second season. Eigner moved on to Brainerdin 1999 and again won coach of the year, this time for Section 7AA in 2006. In his final season with Brainerd, Eigner received the Dave Peterson Award for demonstrating great leadership in the development of youth hockey. Eigner served as an associate head coach at Eden Prairie High School for two seasons, helping the team win the AA state championship. In 2010, Chris Bergeron was hired as the head coach for Bowling Green, and he hired Eigner as an assistant coach. Due in part to the 2008 recession, Bowling Green was considering the termination of its varsity men's team, and Eigner was instrumental in reviving the foundering program. Eigner was tasked specifically with building the defensive corps over a nine-year span and helped to reduce the team's goals allowed from nearly 4 per game in 2010 to less than 2 per game in 2019. In 2019, after the team made its first NCAA Tournament appearance since Eigher's playing days, Bergeron left the team to take an identical position with his alma mater, Miami. 15 days later, Eigner was named the 8th head coach of the BGSU Falcon Hockey program.. To begin the 2019-2020 season, Eigner's Falcons traveled to take on Bergeron's Redhawks in their respective coaching debuts at each school, with Eigner's Bowling Green team taking the win on the road, 7-4. The Falcons won a first round series on the road in Fairbanks, Alaska in March of 2020, sweeping the Nanooks 4-2, 3-2. On the Thursday before their semifinal series against Bemidji State, the WCHA and NCAA announced that the rest of the season was canceled due to the COVID-19 outbreak, ending Eigner's first season in charge with an overall record of 21-13-4. After having a difficult January, the Falcons finished with a 10-game unbeaten streak, longest in the nation. That year, Eigner coached defenseman Alec Rauhauser to his second WCHA Defensive Player of the Year award and a 2nd-team All-American finish, adding to his successful track record of developing tremendous defensive hockey players. Also in 2019-2020, the redesigned Falcon power play unit scored the most goals in Division I, and Eigner helped Connor Ford to be named to the All-WCHA Third Team.
