Second-string and Small fry

Second-string adjective - Being a replacement or substitute for a regular member of a team.

Small fry and second-string are semantically related In some cases you can use "Small fry" instead an adjective phrase "Second-string".

Small fry noun - A young person of either sex.

Second-string and small fry are semantically related in insignificant topic. Sometimes you can use "Second-string" instead an adjective phrase "Small fry", if it concerns topics such as inferior, minor.