my novelty in one of the Scandinavian mainlines


The idea is most probably 3...Nxd5 4.c4 when Black does not have ...Nb4.
Still, Black should have no real problems, and of course Black can take on d5 with queen, when 3.a3 is starting to look silly.

An idiot would surely play 4...Qa5 in your line. Any sensible player would rather play 4...Qd6, where the move a2-a3 is completely useless.