Monster Energy Attack Kawasaki's Jamie Hacking has joined Rockstar Makita Suzuki's Mat Mladin on the sidelines after withdrawing from the Tornado Nationals over safety concerns of the Heartland Park Topeka road course.Hacking made the decision after clocking the 30th fastest time, out of 49 Daytona SportBike riders, in this morning's practice. Of his five laps at speed on the 2.5-mile, 14-turn road course, his best was a 1:43.019 on the final lap. Team Graves Yamaha's Tommy Aquino was fastest this morning at 1:39.440, with M4 Suzuki's Martin Cardenas fastest in afternoon qualifying at 1:39.012.Hacking, who earlier this year was fined and suspended for "conduct detrimental to the sport" over an incident at Auto Club Speedway, wasn't available for comment. The veteran, who's always been at the forefront of track safety, relayed his concerns to AMA Pro Racing Vice President of Competition Roy Janson. Ironically, it was Janson who overheard a private conversation Hacking was having with his wife, Rachel, that led to his suspension and fine.Teammate Roger Lee Hayden, who qualified 14th, may yet have a teammate for the weekend. Argentine Leandro Mercado, who had visa problems just prior to Laguna Seca, may be on his way to Topeka, according to Monster Energy Attack Kawasaki team owner Richard Stanboli."He got his visa. His visa problems are resolved," Stanboli said, adding that Mercado and his father were at the embassy in Buenos Aires with their bags packed ready to take the next overnight flight, if they clear one final small hurdle. Mercado could arrive as early as Saturday morning.Mladin withdrew after riding a few laps during Thursday promoter practice, leaving teammates Blake Young and Tommy Hayden to represent the Rockstar Makita Suzuki team.