Yes. BUT, it must be hooked to Port 1 on the splitter. So take the cable off Port 1, move it to an open port. Then use a short jumper to connect Port 1 to the "Power to SWM" port on the power injector, and use the port cap that you removed from the open port to cap the "Signal to IRD" port on the power injector.
Another way to do it is to take the cable off the INPUT port of the splitter, and connect it to the "Power to SWM" port, then use the short jumper to connect "Signal to IRD" to the splitter input.
Either will work just fine. Option 2 just doesn't take up a port on the splitter. Use option 1 to avoid using an extension cord..
(I know, my wiring closet is a bit messy right now)