We have him and Forrest. Name me one other who has made more than 3 appearances this season? Honestly, it's a bigger problem than you think.
There may not be a precedent but IF (and it's a big IF) a multi million pound bid was recieved (and whose to say any of these rumours are true) then the Celtic board will (and wouls have to as a PLC) give it serious consideration. Unfortunatley, Celtic are ran as a business where shareholders dividends and profits come first! So, if a sizeable profit can be made (without a major impact on the playing squad) then the player will probably be sold. However, as you say - these are merely rumours (and we should wait til we hear anything from official sources such as Celtic!). PS You could have changed your username without setting up a new account
For this season to comply with the U21 rule players must be born after 1Jan1990. So of the first team "regulars", Forrest, Matthews, Wanyama and Rogne all count.
