Second string and Undersized

Second string noun - A squad of players that are available either individually or as a team to relieve or replace the players who started the game.

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

Undersized adjective - Of a size that is less than average.

Second string and undersized are semantically related. Sometimes you can replace phrase "Second string" with "Undersized", this terms are similar.