Is "SUB" a position?

What are the characteristics of a good sub?

To me - young players as the sub simply does not work. They come on and it takes them too long to pick up the pace of the game...they make mistakes and it costs teams badly. As I noted on another thread, subbing Erasmus into the game 100% contributed to Freo losing to Port by a kick a couple of weeks back.

But if that is what doesn't work, what DOES work???

My thoughts:
- Sub MUST be able to go into CBD. No point having a sub who cannot influence at the source with fresh legs/energy.
- Sub MUST be a 'link' style player. Subs need to RUN - no point having a contested ball winner...it's LEGS that are the differentiator...get someone on who can RUN and Link Up (by hand or by foot).
- Sub MUST have the capacity and WANT to kick a goal. You want a sub who pushes hard forward and looks to change the course of a game.

I think we have three (yep, 3) sub candidates on our list right now:

1/. Caleb. He could be the best sub the world has ever seen. Bring him on 10-minutes into the 3rd...
2/. Baker. Runs, kicks goals. COULD go to CBD if we got him to craft with that group.
3/. Scott. Runs, kicks goals. See above re- CBD.

I think West and Weightman also fit the bill, but they are starting 18 fixtures rn.

Those 3-players probably hate being singled out, but if you believe it is an important role, well...