Carroll joined the Hammers on a permanent deal from Liverpool last month for an undisclosed fee, coming through a medical despite being hampered by a heel injury after his season-long loan.
The England international is yet to feature for Sam Allardyce's men in their pre-season campaign, which continued with a 3-0 victory over Boreham Wood at Meadow Park on Wednesday evening.
And assistant manager Neil McDonald admitted after the friendly, in which Ravel Morrison, Ricardo Vaz Te and Kevin Nolan found the net, that it may be some time before Hammers fans see the powerful forward in action.
McDonald told Sky Sports News: "He is well under way in his rehab, he is working hard on the training ground and we just have to be a little bit patient.
"The injury that he has is quite extensive and it takes time for the body to heal itself. He is doing everything he can to push on.
"He has been working really hard and there is still plenty of time for him to get himself fit for the start of the season."
McDonald also admitted that the Upton Park outfit were looking to make further additions to their squad ahead of the new campaign, which kicks off next month with a home date against Cardiff.
He added: "The manager and the hierarchy are working very hard behind the scenes to strengthen the team even more.
"If we can bring one or two others in to give competition for places we will be in a really good place come the 17th of August."