Got a player in on a 5 month loan who is now injured for 3 months so want to get rid but can't see this under Contract? Is this a new thing on FM15
1) It could be to do with a league rule about loans having to end in a transfer window. So you can only terminate the loan during the transfer windows.
2) Presuming this is a player that you loaned from a club, did you pay a fee at all for the loan? If so, I don't believe you can terminate the loan. The "Can be recalled" option is for the club who has loaned the player to allow them to take the player back if they suddenly needed him.
This is where you terminate loans: