SANTA CLARA -- Five-time Pro Bowl left tackle Joe Staley confirmed Wednesday what appeared obvious for the past several seasons inside the 49ers' locker room.

Many of the players were not having a whole lot of fun working in some of the previous 49ers regimes. But, now, Staley said there is clearly a purpose within the 49ers, and he feels a rebirth.

“The energy is back in the building, the excitement level, the attention to detail,” Staley said just moments after the 49ers’ final practice of the offseason program.

“This might sound kind of bad, but I’m enjoying football again. I’m excited to come to work every single day. The last couple of years, there were days when I couldn’t honestly say that. That’s awesome to have that feeling back.”

The biggest reason for Staley’s renewed enthusiasm, he said, is coach Kyle Shanahan, whom he called “the smartest coach I’ve been around.”

First, Shanahan impressed Staley with his honesty. He kept tight end Vance McDonald in the loop when there were trade talks during the weekend of the draft. And Staley said he holds all players to the same high standards.

“He calls out myself and (NaVorro) Bowman the same way he calls out a rookie free agent,” Staley said. “No one’s above anybody.”

Players on both sides of the ball have expressed their amazement with Shanahan’s unique ability to break down a play from the perspectives of every player on offense and defense.

Staley said he had one of those moments Wednesday during a team meeting when Shanahan dissected plays for both sides of the ball.

Said Staley, “Even today we had a meeting, and I looked over at (Daniel) Kilgore – I was sitting next to him in a team meeting – and (said), ‘This is awesome.’ You get chills, almost.

“It’s cool to see football talked about that way. Instead, of ‘Hey, you have to do your job.’ ‘OK. Yes, sir.’ ‘Why do I have to do my job?’”

Staley said Shanahan is able to pinpoint the details of every play that determine why it is successful and articulate it in an easy-to-follow manner.

Staley has been familar with Shanahan's system for a while, he said. He has watched film of offensive tackles Trent Williams and Joe Thomas, who played in Shanahan’s offenses with Washington and Cleveland, respectively.

“I felt I’d be a good fit,” Staley said. “(I’m) excited, but kind of bummed it’s happening in Year 11, and not Year 4 or 3 or 1.”