If you don't mind losing that cup, I'd cut the plastic and pull it out. That way you can get a better idea of what you're dealing with. It's obvious that it wants to live. I think as long as you're gentle with it you'll be okay. Good Luck!

Tim

I'd guess it has all kinds of roots through the drain hole.
Most times they are small enough you can VERY carefully feed them through the drain hole.
I just loosen the main plug and with a gentle pull feed the roots through the drain as i pull the plant out of the cell.

A plant that got that big with no attention is not going to be slowed down by a little root damage.
The smaller plant looks easy to just treated as usual.
Loosen the cell and pull it up.

I use 9 cell incerts for my 72 cell trays.
I like them a lot.
I just have to mess with a 9 cell tray instead of a 72 cell one that is full of sprouts...

Inserts for bigger trays are a pain.
A couple of 9 celled ones in the same container is WAY easier.
I get my smaller celled stuff at the $.99 cent store-pack of 5 (i think) for a buck + tax.
Much easier to deal with.
They fill a 54 or 72 cell tray(any combination of 9 cells).Then there is always cutting them up,if need be.

http://s403.photobucket.com/user/smoemaster_2007/media/2011%20pics/PICT2035.jpg.html?sort=2&o=164

The link is to small starter trays that take the same room as a big tray but I only have to deal with smaller trays when Annuums or whatyever seed grows faster than the rest.

Here is a link that might be useful: I use these too.