kirschke was selected by the detroit lions as an undrafted free agent in 1997. in his rookie season he played in three games making his nfl debut on august 31 against the atlanta falcons. he finished the season with one tackle. in 1998, he spent the majority of the season on the injured reserve list and did not get any playing time. the following year, he played a far more active role in the lions starting line up with seven starts and 15 appearances. he finished the campaign with 20 tackles and two sacks. in 2000, he played in 13 games recording 13 tackles and 0.5 sacks. in 2001, his fifth season with the lions, he played in all 16 games making 20 tackles. in his final year with the lions he made 15 appearances and 19 tackles.