TMZ has learned Eva Mendes is in Utah battling a substance abuse problem.

We're told the "Ghost Rider" star is at the famous Cirque Lodge, near Sundance. The Lodge, which treated Lindsay Lohan and other stars, is one of the most respected treatment facilities in the country.

Since then, Mendes' rep has released the following statement:

"Eva has been working hard for the past year and made a positive decision to take some much-needed time off...