ALLEN PARK, Mich. -- It took a few days, but the Detroit Lions had their first padded practice of the season Sunday and immediately some things became apparent.

The Lions have a bit of work to do on the offensive line (more on that below) and both Marvin Jones and Golden Tate should be in good shape this year.

Here are some thoughts and observations from the day that was Sunday in Allen Park, Michigan.

The Lions' offensive line struggled during the team's first padded practice of training camp. AP Photo/Duane Burleson

1. What a rough day for the offensive line: It was not a good first padded practice for the Lions offensive line. In team drills, the defensive linemen routinely got through blocks to help blow up plays from both starters and reserves. When it came to the offensive-versus-defensive line drill, which is one of the most exciting drills in camp, it got a lot worse for the offensive line. By my unofficial count, the offensive line won just seven of 26 reps on Sunday. Riley Reiff had the best day in the drill, stopping Devin Taylor once and holding him to a tie in his other rep. The interior of the line struggled often and after a good first rep against Ezekiel Ansah, left tackle Taylor Decker had Ansah blow by him the second time around. Then, on the last rep, Decker lost to Quanterus Smith fairly handily. To understand the drill completely, here's what I wrote about it last year to give an indication of its importance.

2. That is, except for Reiff: I didn't see this, but Caldwell brought it up so it is worth mentioning. Apparently Reiff broke at least one, if not two, face masks during Sunday's practice. Caldwell used that as an example of Reiff remaining intense despite being moved from left tackle to right tackle this offseason after Decker was drafted.

"Riley is a warrior," Caldwell said. "Riley does not care about anything other than wanting to play his position and play it well and he doesn't care where he plays. He's a talented guy that's tough and hard-nosed, the exact kind of guy that you're looking for to lead your group."

3. The receivers, meanwhile, had a good day: Both Jones and Tate had highlight-level catches Sunday. While the Lions knew they were getting a good receiver in Jones, he has done pretty well the past couple of days when matched up against Darius Slay, potentially a good sign for Jones' development in Detroit's offense. In one-on-one drills Sunday, Jones beat Slay off the line, kept some distance despite good coverage from Slay and caught a perfectly placed ball from Matthew Stafford for what would have been a touchdown. In 11-on-11 work, Tate had a jumping catch on an out route over Nevin Lawson and while it was on the far side of the field, it appeared he stayed in-bounds. He also had a good catch over the middle on a slant from Stafford. Like always, Tate catches nearly everything thrown his way. Overall, I didn't see too many drops Sunday after a tough day for pass-catchers across the board Saturday.

4. Theo Riddick sat out: It doesn't seem too concerning at this point, but Riddick missed the first padded practice, one of two Lions players not on the NFI or PUP list to sit out Sunday. Riddick declined comment after practice as he was walking inside Detroit's weight room. Lions coach Jim Caldwell said Riddick has "got a little bit of an injury, but he'll be OK." The Lions have typically been extra cautious when it comes to player injury, particularly so early in training camp. With Riddick having a large role in the offense, the Lions are likely to give him time to fully heal from whatever undisclosed injury he has. Also sitting out Sunday was receiver Ryan Spadola.

5. Some early rotation in the defensive backfield: I wouldn't read too much into it yet, but Johnson Bademosi got some work at outside corner opposite Slay with the first unit in place of Nevin Lawson and Tavon Wilson received some work as the nickel at the same time instead of Quandre Diggs. There have been no indications either battle has been close, so it was likely a matter of getting some more film on two guys the Lions might eventually need defensively this season versus any sort of competition starting up. But it'll be something to keep an eye on as camp goes on.

6. Stafford looks sharp:While his offensive line had a tough day, the Lions quarterback once again looked pretty good. It feels like I write this type of note at points during every camp, but he seems to have pretty good command of Jim Bob Cooter's offense at this point. While I didn't catch 7-on-7 work Sunday in favor of the one-on-one line drills, Stafford completed every pass I saw Sunday. During the last period, though, he did fumble on what would have been a sack if hitting quarterbacks were allowed. But once again it is obvious how much better he is than his backups.