City were close to completing the deal in the summer, but it was delayed after the 19-year old picked up a knee injury.
Assulin left Barcelona after he was unable to agree a new contract, and the player - who was dubbed 'the new Lionel Messi' when he was coming through the ranks in Catatonia - attracted attention from a host of clubs.
But it is City who look to have won the race the sign the Israeli international, a further signal of their intent to become one of the biggest clubs in Europe.
He had a medical at Eastlands last week, and was then sent to a rehabilitation centre to quicken his recovery from the knee problem which scuppered his summer move.
City are now satisfied with his fitness and hope to confirm the deal in the next few days.
It is reported that Assulin will sign a four year deal with City. He will not need a work permit as he holds a Spanish passport.