You got Henderson, Allen, Rossiter and a couple more there. If you need a top class CM, I reccomend someone like Modric? if you got the money. As cover, you could get Strootman
Give Rossiter game time with either Pirlo or Allen as a 2nd pairing and maybe put a 3 man midfield as your 2nd or 3rd tactic and use Hendo, Allen and Pirlo there and Rossiter as backup. if you do have a 3 man mid, you need extra cover.
Im near the end of second season and Gerrard is going to retire, so I need replacement for him. My first choice would be Strootman but he may cost a lot.