Originally Posted by DMPHL

Have a look at the Iberia flights. On a random day I checked, they have a 4:45PM flight from Chicago (IB6274) to MAD connecting to BCN on flight (IB3012), with a 3.5 hour connection in MAD. The corresponding AA flight numbers are AA8651 and AA8693, respectively. I'd keep an eye on those and if you are at ORD and the plane is looking like it's going to be late, ask to be put in J on those flights, assuming there is space.

I usually give the AA flight numbers just so that I don't immediately have an agent who might be clueless tell me they can't book on another airline. Also note that in the case of same-day IRROPS, especially mechanical, they usually don't need to have the discounted fare class available. They might want you to just go to Miami and become MIA's problem, but absolutely talk to agents at the Admirals Clubs (try both if you need to) and the service desks if necessary.