West Ham are allegedly refusing to meet AC Milan's asking price for the striker.
The Hammers are keen to add a striker to their squad this summer and have been linked with a number of names across Europe.
They have already had a bid rejected for the Colombian forward according to Sky Sports, after bidding €20 million, around £16.2 million for his services.
The Italians are hoping to get as much as £21.2 million for their man according to CalcioMercato and according toSky Italia that has led the two clubs into a standoff over their valuation of the player.
Milan are refusing to lower their asking price, while Slaven Bilic’s side are unwilling to increase their original bid to match it, with neither side willing to move at this moment in time.
It now remains to be seen if any compromise can be made over Bacca, with the Hammers likely to look elsewhere in the meantime.
It may be unwise to stall on a deal for the Colombian though, with him likely to attract interest from other teams across Europe given the form he showed in Italy last season.