Looking to replace high rated linebackers that aren't performing well

We play three linebackers.  I have Wagner and Singleton.  Looking to possibly replace Kirksey and Vanderesch.  Neither have been doing that well.  What do you think of AJ Klein and Troy Reeder (who replaced Kiser on IR).  Klein has played well of late and Reeder had 15 tackles on Sunday (better than what Kiser was doing)?  Thanks for the help.