Bruce Arians revealed the Tampa Bay Buccaneers were "never really dreaming" Tom Brady would become available as they entered NFL free agency.
Brady, 42, has joined the Bucs on a two-year contract after spending 20 years with the New England Patriots, for whom he won six Super Bowls and nine AFC Championships.
As the quarterback was introduced on Tuesday, Bucs coach Arians explained the team had looked at every option at the position, as they ultimately moved on from former number one overall pick Jameis Winston.
They knew Brady would be their top priority if he opted to leave the Pats, but they did not truly believe it would happen.
"We do our due diligence every year after a season to see how we can better our football team and better our organisation," Arians told reporters.
"We looked at everybody that might be available at the quarterback position, obviously really never dreaming that Tom would be available.
"But if he was, he was he going to be our number one choice."
While Arians is a huge fan of Brady's playing ability, it is the veteran's leadership that he craved most for a Bucs franchise without a playoff appearance since 2007 and with only one Super Bowl victory in their history.
"He can make every throw and do everything that we want to do in our offense but more than that it was his leadership ability that we need in our locker room to get where we want to go," said Arians.
"So once that [bringing in Brady] became a reality, it was see what we have got to do and see if we can get this done.
"To have Tom lead our football team into the future… I have been very, very blessed as a coach to have been around some of the great ones and now [I am blessed] to have the greatest one of all time.
"Not for me because of what he does on the field but because of what he does to his team-mates.
"He makes everyone who walks into that huddle better. I'm really just excited to get started. I'm extremely excited and wish we could start practice tomorrow."