"Frankly, I feel this — and I've thought it since I came back in April; it started in the weight room — this team has a different edge to it, a higher sense of urgency than I can recall," McCarthy said Tuesday.
"I don't know how to sit down and measure it and put it on a scale each year. Maybe it's my higher sense of urgency."
Indeed, according to quarterback Aaron Rodgers, that attitude adjustment starts at the top, with McCarthy.
"I think Coach is doing it and he's leading by example. I think he set the tone when we came back in April, and he set the tone when we came back in May off our break," Rodgers said.
"We sat down, we talked about the direction of the OTAs and what we did last year didn't work and what we'd like to see. I think you have to give him credit for the schedule and the tempo and setting the direction. He's done a good job with that, and the guys just follow his lead."
After winning the Super Bowl after the 2010 season, the Packers have lost in the divisional round in the past two seasons.
In 2011 after a 15-1 regular season, they lost at home as the NFC's No. 1 seed to the eventual Super Bowl champion New York Giants 37-20.
Then last January, the Packers couldn't stop 49ers quarterback Colin Kaepernick and the 49ers. He rushed for 181 yards and two touchdowns in San Francisco's 45-31 win.
After the loss to the 49ers, Rodgers expressed concerns on his weekly radio show in Milwaukee about the tone he got from the team in the two seasons after the Super Bowl victory.
The Packers' practices that have been open to reporters have appeared more spirited than past offseason workouts, in part because there is greater competition on the roster.
Several familiar names left during the offseason — wide receiver Greg Jennings signed a free-agent deal with the Minnesota Vikings, receiver Donald Driver retired and veteran defensive leader Charles Woodson was released — leaving voids that must be filled in the locker room and on the field.
"You can look at James and (me) and Randall. Everyone's going to talk about missing Donald and Greg — which we will, it will be an adjustment — but we know we have an opportunity to step up and we have beliefs in what we can do."
There's also the belief that the Packers had Super Bowl-caliber teams each of the past two years and failed to deliver.
"Guys know there's a short window for a team to be as good as we are," Nelson said. "You've got to make the most of those (years) and that's by winning championships. We know we've been close. We know we've had the team, but came up short."
In an effort to avoid that same fate, the Packers have made some changes. McCarthy reconfigured his offensive line, taking four starters and moving them to four new positions.
The defensive coaches not only spent much of the offseason working on solving the read-option that the 49ers used to beat them, but also emphasized increasing takeaways, especially forcing more fumbles.
And with the addition of two big-name running backs in the draft — second-rounder Eddie Lacy of Alabama and fourth-rounder Johnathan Franklin of UCLA — McCarthy said that the running game will improve, which would help Rodgers and the aerial game.
"We'll be better, I promise you that," McCarthy said of the run game. "You can write that down. In big letters."
Whether their renewed sense of urgency leads to an improvement and another Super Bowl berth remains to be seen, but McCarthy insists the team is in a good place with the opening day of training camp 45 days away.
"You learn from your past experiences," McCarthy said. "Every team is different, every year is different, every challenge that we'll face will be different. There are opportunities to look back to the past that will help us encounter and conquer those challenges that are in front of us."