At 24, former Georgia Bulldog star football player Asher Allen, perhaps visualizing health concerns in the future, alerted Minnesota Vikings head coach Leslie Frazier that he’s retiring.Allen, a three-year defensive back with the Vikings, has yet to say why he is quitting his profession, but he did suffer concussions in back-to-back seasons. With Junior Seau’s recent suicide and Dave Duerson’s and others — all because of brain injuries from playing football, it makes sense that Asher would give retiring as an option.But to do it at such a young age is surprising. Frazier said, “He’ll talk about it more at some point. But he explained to me that this was something he wanted to do. He had given it a lot of thought and that’s what he wanted to do.“I didn’t see that coming. But everybody has to make decisions that are the best for their family.”Allen became a starter last season after injuries hit the Vikings. He played in 12 games and started nine. The 2009 third-round draft choice added depth to the secondary.