My wife and I have a return flight in J from Europe that is ending is MSP after layover ORD. Our final destination is SAN but in order to book a magic low-tier award we ended the flight in MSP. We booked a one-way ORD-SAN to get us home much sooner planning to skip the final ORD-MSP award segment. However Delta switched my itinerary and now we are on the same flight ORD-MSP in R and ORD-MSP-SAN in T.

What is going to happen when we show up at ORD for the Flight? Any suggestions?