Player Recommendation

Plenty of options. But rather than go and chase the replacement of specific cards. Think about whether you just want to enter the OVR race or if you want to get a themed squad.
I go for themed squad - Juve Icon/Hero cards only, so this event has 3 cards for me.  Rush (although he played one season), Vieira and Tevez. Will likely get all 3 because I packed Rush from the gem pack and should be able to get enough shards for the other two (might have to dump some gems to make the difference). Personally, having a team full of players you watched over the years, is more fun than chasing the OVR game, which you are quite far behind anyway.
Rush is pretty decent for a 114 card (only trained him for now, and he's doing quite well imo).

I think some excellent suggestions from RaisingHell13.. If I were u I will go for Reece James as LB/RBs don't get outdated that quickly, so will last you for a couple of months.  

King is still good and with a CDM I think defence should hold good, so I suggest replacing Fermin next (Don't know how he plays, purely based on OVR).

If you can go up to 1150 may be pick Rush+Enzo Fernandez instead.

Go with defense first always, you won't regret it. As for card do you play more on right, left or through the middle? If right then I suggest strengthening right back ,maybe get Reece James, but he is only 800 I think but then you can get another good card for like 200 shards like Dempsey, Gordon, Estevao, O'Reilly or Cahill, all have great pace. But if you just want a single card then either CAM or CM (if you like this formation) like Palmer or Rooney OR CB if you want to go with defense then get Gabriel or Moore (he has amazing pace but you have to figure out how to use him). Or if you OVR chasing then you can get 2 114 card being Keane CDM + Rush at ST for 500 shards each, which will give you 2 119 potential players. But up to you, follow your heart lol.