I think he is saying that he buys some players but they end up not performing well but he can't sell them on his level/server so he would like a bigger squad size so he could sit them on the bench and play newly bought players.
Interesting bit of info to remember for 19 seasons time though!
Watford Boys FC
Season 1 - League Champions
Cup Winners
Season 2 - League Champions
Champions League Winners
Season 3 - League Champions
Champions League Winners
Cup Runners Up