"The energy in practice is I think double what it was last week," Tuck said Thursday. "Guys seem to be a little bit more excited about playing football. I think last week we were a little sluggish."
The Giants lost their regular-season opener at home against the Dallas Cowboys, 24-17.
Jason Pierre-Paul and the Giants couldn't get to Tony Romo last week.
When asked how the defending Super Bowl champions could be sluggish in Week 1, Tuck said, "You're asking the million dollar question. I don't know."
"Sure it's a fair question, and I wish I could give you the correct answer," he added. "Some things are unexplainable."
Giants coach Tom Coughlin, who admitted being unhappy with his team's practices prior to the Cowboys game, agreed that the team has looked better this week.
"Yesterday, the effort was very good," Coughlin said. "Today was, for the most part, pretty good -- I didn't think the last period was good. The effort, again, and the focus was better."
One of the most startling aspects of the Giants' loss to the Cowboys was the team's lack of a pass rush. The Giants recorded 48 sacks last season -- tied for third in the NFL -- and feature three of the most feared sack artists in the league in defensive ends Jason Pierre-Paul, Osi Umenyiora and Tuck.
But last Wednesday night against Dallas, that trio didn't record a single sack. In fact, they didn't even record a quarterback hit.
"That's alarming," Tuck said. "That's not how we play football."
The Giants gave the Cowboys some credit on Thursday. "They played well," Tuck said. "Their offensive line played great."
But they also gave you the impression they tried to do too much against Dallas -- going for the big play individually, instead of doing what's ultimately best for the team collectively.
"We've just got to go out there and not try to do nothing extra," Pierre-Paul said. "Don't try to hit the home run. Don't try to get a sack going inside. Handle your responsibility and do your techniques."
"In this past game, they were getting the ball out quick, and we knew that," Umenyiora said. "So we should have done a better job of getting our hands up. We weren't gonna be able to get to the quarterback in a lot of those situations, so we should have got our hands up and try to knock the ball down."
"I think we pressed, trying to make plays," Tuck said.
Their defensive coordinator, Perry Fewell, said Thursday that he hasn't had to remind his three star defensive ends about their failure to produce in Week 1.
"That's the great thing about those guys," Fewell said. "The pride that they take in hits on the quarterback, sacks and doing what they do."
This Sunday they'll be chasing Tampa Bay QB Josh Freeman, who piloted the Bucs to a 16-10 over the Carolina Panthers to open the regular season. Freeman, 24, is dangerous on his feet -- fifth among NFL QBs in rushing yards in 2011 (238 yards), and second in 2010 (364). He also had four rushing touchdowns last season.
The Giants expect to give Freeman a lot more problems than they did Tony Romo one week ago. The stakes are high -- according to ESPN Stats & Information, just 12 percent of teams starting a season 0-2 (22-184) have made the postseason since the playoffs expanded to 12 teams in 1990.
"We know we're a better defense than the way we went out there and played," Umenyiora said. "We didn't execute. We're coached better than that, and we're gonna play better than that on Sunday."