He is not happy, however, that Ulberth is the Rathgar's champion in the contest. Bjorn rather suspects that Ulberth will engage in treachery in this contest, perhaps cheating, perhaps even setting up his men to ambush Bjorn. Especially since the shaman said that bit about "no other rules." Bjorn also worries about what will happen to Wulf alone in the village.
Because he is the older brother, Bjorn automatically assumes that he will do the racing--he usually takes the leadership role. He still thinks of Wulf as his little brother and it hasn't entirely registered with him that Wulf is now a grown man.
Bjorn steps forward and says, "I will drive the sled. May I ask who will be keeping watch over my little brother? It is easy for rumors to start during such things as this. Some might think I have treacherously fled, when I have not, for instance. Someone who is quick to anger at such things might kill Wulf in his wrath, not waiting to find out the true results of this contest. May I request that someone of even and calm temper keep watch over my brother?" Bjorn sort of glances at Jarle and his followers.