Gutter Boy
Tim Sherwood
I believe a team can only allow forwards to blow hot and cold, your midfield must control game if they are off the whole team suffer.
But we're not talking about Biss being a starter any more. He (along with Bentancur) is the senior figure taking secondary minutes while Gray establishes himself in that position. Biss seems better in short bursts, rather than prolonged periods in the team, so that might actually get some of the best out of him.
For players to sub on at 70 minutes, and to play midweek games (if we have any next season), I'm not sure we'll find better than those two.