second stringer

The phrase "second stringer" typically refers to a person who is not a part of the main or starting lineup or who holds a substitute position on a team or group. It can be used in sports, where it describes players who are not part of the starting team but serve as substitutes or backups. In a broader context, it may also apply to anyone who serves as a backup or substitute in other fields, like work or social settings, where they are not the primary choice or first in line.