Manchester City reportedly want a new striker, with Sergio Aguero's contract expiring at the end of the season, and there are doubts whether he will sign a contract extension or not, as there is growing interest from Paris Saint-Germain and their new manager, Mauricio Pochettino.
Reports from The Daily Telegraph states that City are searching for a replacement to Aguero, and Lukaku has become the priority over other options.
The 27-year-old has starred for Inter ever since moving to the Serie A from Manchester United, and it easy to see why Guardiola is keen on a move for the Belgian, yet it remains to be seen whether Lukaku will actually want to move to his former club's rivals.
Inter will also want a very hefty fee for Lukaku, with him being one of their most important players in the whole squad, and especially since they paid £71.1 million when they signed him from United, and he also has three-and-a-half years remaining on his current contract.
Lukaku has had a magnificent season so far, scoring 17 goals and providing three assists in 23 games in all competitions, with his 12 Serie A goals being only second to Cristiano Ronaldo's 15 league goals this season.
Lukaku was excellent last season as well, where he scored 34 goals and provided 6 assists in 51 games in all competitions.