LA Galaxy are struggling to sell out their 27,000-capacity stadium for this weekend's pre-season friendly against Manchester United.
Free agent Ibrahimovic is now recovering from knee surgery at Manchester United's training ground.
A reported £6m-a-year contract was offered to the 35-year old, with Richard Keys reporting that the deal was as good as complete, but Onalfo has moved to squash these rumours - saying: "Our policy is not to comment on players that are not part of our team".
Jose Mourinho's men will play a total of eight games in eight cites and four different countries - the United States, Norway, Ireland and Macedonia - over 24 day period as they prepare for the 2017/18 campaign.
Mourinho will face the media for the first time on tour at United's base on the UCLA campus on Friday to discuss the £75million signing of Romelu Lukaku and his plans for the rest of the summer.
The five-time MLS Cup winners may be forced to downgrade Ibrahimovic's basic wage to ensure he can be added to their squad during the second transfer window of the year, which runs from 10 July-9 August. MLS clubs are allowed a maximum of three players whose wages exceed the club's salary cap, but those positions are now occupied by Romain Alessandrini, Giovani dos Santos and Jelle van Damme.
Ibrahimovic, who turns 36 in October, was United's top scorer last season with 28 goals.