Jenson Button pulled out of a triathlon on the Canary Islands last weekend.
The McLaren driver, participating in the event at Fuerteventura in the gap between the Chinese and Spanish grands prix, completed the 1.9km swim and 90 kilometre bike legs without trouble.
But Button, 34, pulled out during the half-marathon with 'muscle problems' in his leg, according to specialist media reports.
With less than two weeks until the Spanish grand prix at Barcelona, McLaren has been contacted for comment.
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