LC load balancing three links through a router

first,

 

I recommend is that you have 3 routers, there is no logic to have 3 links in a router.

 

 

But can you do the following.

 

 

configure a trunk link between the router and LC.

 

there you will have 3 links.

 

You know very well the networking so you wont have problems.

 

 

http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos_management_guide_10_1/tmos_trunks.html