Yes. Since you're not running any stereo stuff, you could split the path after the last effect, put the IR on that split path, then route the top path to the left out and the IR path to the right.
Another option would be to use one of the sends. If you are using it in 4 cable configuration, you'll be using at least one of the effects loops, but if the other is free, you could place the send from that loop before the IR in your path and that send would be the thing going to your amp's effects return. You don't have to do a split that way, so you'd be able to use the split path for other purposes if you wanted.