Serna was signed by the Winnipeg Blue Bombers on June 3, 2008, to compete with embattled 17-year veteran Troy Westwood in training camp. After Westwood was released in training camp, Serna became the lone kicker/punter on the roster. After starting his pro career 7 for 7 for field goals, he followed by going 10 for 20 and making 17 of the remaining 24 of the season to finish 34 of 51. He became heavily criticized by the media, by then head coach Doug Berry and public at large during his mid-season struggles.