ALLEN PARK -- One day can make a difference when it comes to rust and trust. One year can do a whole lot more.

After Sunday's opening to Detroit Lions training camp offered somewhat of a clunker for the crispness of the passing game, Monday's practice delivered some of the looks expected from a team gearing around throwing the ball. Eric Ebron was out after tweaking what appeared to be his hamstring Sunday, but the substitution of Darren Fells resulted in no lost time.

More than the work with the new faces, however, the practice emphasized a bit of what Detroit has in the passing game that it didn't have a year ago.

Matthew Stafford is back for a ninth straight season, of course, and Golden Tate has been doing his high-catch, productive act for three seasons now. But unlike a year ago, Marvin Jones isn't a newcomer to the team's No. 1 receiver spot any more. Jim Bob Cooter isn't in his first camp calling the plays. And Calvin Johnson's void isn't a problem to think about for the first time.

Stafford is still working on a long-term extension, but he's here for another year for sure, and the Lions believe the newness to lots of the passing game is wearing away. It's not just the plays on the field that give hope, such as catches in traffic by Marvin Jones or down the field by Golden Tate. It's the realities of what they don't have to create from scratch.

"Now, we're focusing on details that last year we couldn't even think about trying to figure out," Tate said. "For instance, knowing the hots and sights without having someone indicate them to us. I think we're just really, really dialed in and trying to take stress off of Stafford and other guys."

The Lions passing game was productive for stretches of last year, as Stafford gained MVP hype with a 23-touchdown, 7-interception start through the first 11 games. It stalled out in the final month when Stafford dislocated the middle finger of his throwing hand, when the biggest games popped on the schedule and when heavy doses of press-man coverage threw Jones and others off their game.

The playoff contest at Seattle was the low point, when the offense managed six points and four head-scratching drops. It left Jones blaming himself in the locker room, Tate bitter through the rest of spring and Stafford in search of an throwing coach for the first time in his career.

The fruits of those labors, including the time Jones spent learning route running and separation techniques from Randy Moss, have a chance to pay off this season, including a little bit in training camp. The lack of contact and game plans make so much of what happens on the field hard to adequately judge, but the crispness and cohesion of the quarterback throwing to his receivers should remain on display.

"Overall, our passing game is just better," Caldwell said. "It's not where we want it to be yet, but that's part of having guys running routes a little bit better, the timing is a little bit better. Some of those things are starting to click."

It was strong Monday, in part because it showcased some of the changes that took place. In team drills, Tate ran a route down the left sideline when Stafford threw a deep ball into double coverage. With Darius Slay in trail and safety Charles Washington chasing over top, Tate leaped up and caught it in a window he wasn't sure would exist.

"That's a tough throw," Tate said. "For him to do that definitely shows he's getting better."

The Lions know any advancements in the passing game won't matter if Stafford isn't protected, and that remains the primary question with Taylor Decker's months-long absence at left tackle. Detroit took on $9.5-million annual salaries for guard T.J. Lang and tackle Rick Wagner this offseason in order to run deeper and slower-developing routes, but the chemistry of that right side is a constant work in progress after Lang missed spring practices recovering from hip surgery.

The running game is seemingly always a work in progress in Detroit, although Ameer Abdullah appears fluid in the early days of his return from last year's foot surgery. Cooter and the Lions will have to develop ways to fight off defensive adjustments that will later come so something as simple as press-man coverage doesn't derail all they're trying to build.

But the chances to craft it are in the here and now. The ice breakers were last year's games.