Kreider entered the league when the Steelers signed him as an undrafted free agent following the 2000 NFL draft.

After playing on the team's practice squad, he was signed to the active roster on October 17, 2000, to replace Jon Witman, who had been injured.

He remained on the active roster for the remainder of the season and was named the Steelers' Rookie of the Year, playing better than draftees Plaxico Burress and Marvel Smith.

Starting at fullback in Super Bowl XL vs Seattle, Kreider threw a key block for quarterback Ben Roethlisberger on a one-yard touchdown run in the second quarter to give the Steelers a 7–3 lead.

The move reunited him with Cardinals Head Coach Ken Whisenhunt, who had previously been the offensive coordinator for the Steelers during Kreider's time in Pittsburgh.