The England international, 25, developed a sore left ankle during training, according to a statement from the Premier League club.
Carroll will miss West Ham's clash against the Wellington Phoenix in Auckland on Wednesday and the meeting with Sydney three days later.
The former Newcastle and Liverpool striker was hampered by injuries in 2013-14, making 15 league appearances and scoring just twice.
A West Ham statement read: "After assessment by the club's medical experts, it was decided to let the England international rest for both remaining games and receive intensive treatment to ensure he is fit for the start of the season.
"It should be clear that the affected area is not in any way associated with the previous injury he successfully overcame towards the end of last season."
West Ham start their league campaign with a clash at home to Tottenham on August 16.
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