chapter 10 why is King Arthur encouraging THE BOSS to start out on his own quest?

Sir Sagramor le Desirous thiks he has been insulted by The Boss (Morgan). He challenges The Boss to a bout after he returns from his quest for the Holy Grail. King Arthur thinks that Sir Sagramor le Desirous is not ready for such a challenge and encourages Sir Sagramor to undertake a quest of his own in order to be worthy of such a fight.