Nov 17 (Reuters) - The National Football League (NFL) will implement additional COVID-19 protocols in anticipation of the U.S. Thanksgiving holiday, citing concern over an uptick of positive cases. In a memo obtained by Reuters, the league urged clubs to offer drive-through testing for players" and staff members" family and friends visiting for Thanksgiving and said all players, coaches, trainers and others associated with team operations must be tested the Monday and Wednesday following the holiday. "COVID-19 rates continue to steadily increase across the country," the memo read. "This upward trend, coupled with the onset of colder weather driving individuals indoors, has resulted in an increased risk of infection among players and staff." The document, which was distributed Tuesday, said individuals regardless of vaccination status must wear masks inside club facilities from Thursday, Nov. 25, through Wednesday, Dec. 1. "Our experts and data confirm that getting vaccinated remains our strongest defense against contracting and transmission of the virus within club facilities," the memo read. The White House said on Wednesday that 80% of Americans 12 and older have received at least one COVID-19 vaccine dose. read more