Yes. As noted in the configuration guide:
"You can use any unused interface (physical, redundant, or EtherChannel) as the failover link"
The only thing to note for very long distances is down a bit further in that guide:
"For optimum performance when using long distance failover, the latency for the failover link should be less than 10 milliseconds and no more than 250 milliseconds. If latency is more than10 milliseconds, some performance degradation occurs due to retransmission of failover messages."
10 milliseconds is no problem since propagation delay over 50 micron fiber @ 1310 nm is about 5 microseconds/km.
