The invention includes a process for inhibiting deterioration in an olefin polymer by adding a phenolic free radical inhibitor during or before polymerization with a metallocene type transition metal catalyst without inactivating the free radical inhibitor because does not inhibit the transition metal catalyst activity. Preferably the free radical inhibitor is first to remove compounds which inhibit catalyst activity. The invention also includes a composition comprising at least one olefin monomer, a polymer of the monomer, a metallocene type transition metal catalyst and at least one free radical inhibitor having sufficient substituents to hinder the active inhibiting group such that it does not undesirably inhibit the transition metal catalyst.