what type of oak is this?

I just bought a 6 foot Bur Oak in a 5 gallon pot, and there was also a smaller oak tree - is this a macrocarpa also?

 

leaf looks like Quercus lyrata (Overcup Oak)

 

Oak seedlings are very tricky, as their leaves often differ from adult leaves. My suspicions would be perhaps one of the hybrid oaks involving Q. phellos, though, to account for the narrowness of the leaves.

 

For it to be Quercus lyrata the back of the leaf has to be white and softly hairy.