When picking even numbered teams in a sporting game, where two leaders are choosing/building a team, one person at a time from a larger group, the last person will not be able to play if the larger group started with an odd number. This last person is the odd man out. It should also be understood that the last person picked was likely the least wanted (or possibly odd) person in the opinion of the pickers. So, being this person can have a doubly negative feeling. Unwanted and not playing.