The New England Patriots are the betting favorites to sign Tom Brady. The Tennessee Titans are considered the biggest threat to lure the six-time Super Bowl champion away from Foxborough. Other teams are preparing to make a potential run at the quarterback in free agency.

NFL teams are allowed to negotiate with agents of potential free agents on March 16. Players can officially sign with new teams on March 18.

March 12 is an important date for Tennessee. That’s the final day in which the Titans can use the franchise tag on Ryan Tannehill. Doing so would prevent the quarterback from hitting free agency, giving the two sides until July 15 to agree on a long-term contract. The franchise tag for Tannehill is a one-year contract with a guaranteed salary of close to $27 million for the 2020 season.

According to ESPN’s Jeremy Fowler, the Titans believe there’s a good chance Brady will choose them over the Patriots. Tennessee reportedly still value’s Tannehill, though they might not want to pay him the type of salary he’s seeking.

Tannehill led the NFL with a 117.5 passer rating in the regular season, going 7-3 as a starter before reaching the AFC Championship Game as the Titans’ signal caller. Tannehill could be seeking a new deal that pays him close to $30 million per year in free agency.

A “mystery team” is in the mix with the Patriots and Titans to sign Brady, according to Fowler. It could be the Tampa Bay Buccaneers or Indianapolis Colts, both of whom could be players for Brady or Philip Rivers.

Tampa Bay is weighing its options at quarterback with Jameis Winston headed for free agency. Winston led the NFL with 30 interceptions in 2019.

Indianapolis could look to replace Jacoby Brissett a season after he inherited the starting job from the retired Andrew Luck.

The San Francisco 49ers are unlikely to be among Brady’s top suitors. The quarterback might like the idea of joining the reigning NFC champions, but San Francisco is expected to go forward with Jimmy Garoppolo as its starting quarterback.

Garoppolo had a top-five passer rating, completion percentage and yards per attempt in his first full season as the 49ers’ starter. San Francisco went 13-3 before blowing a fourth-quarter lead to the Kansas City Chiefs in the Super Bowl.

Brady led the Patriots to a 12-4 record in the 2019 season. He threw for 4,057 yards, 24 touchdowns, eight interceptions and an 88.0 passer rating.

Brady is 11 years older than Tannehill and nearly 15 years older than Garoppolo.

Tom Brady
In this picture, quarterback for the New England Patriots, Tom Brady, celebrates after winning Super Bowl LIII against the Los Angeles Rams at Mercedes-Benz Stadium in Atlanta, Georgia, Feb. 3, 2019. TIMOTHY A. CLARY/AFP/Getty Images