Some thoughts heading into the weekend on the Detroit Lions and the first week of the new league year:

1.There’s still a lot of time between the draft and free agency for the Lions to upgrade their roster. Right now, though, there are still too many holes to fill. Detroit replaced Ndamukong Suh, Nick Fairley and -- for now -- C.J. Mosley on the defensive line with Haloti Ngata, Tyrunn Walker and a player to be determined. That doesn’t seem like an equitable tradeoff, at least right now. There are still questions on the offensive line and cornerback, too. There is still time for the Lions to make improvements -- James Ihedigbo was not a first- week signing last season, for example -- but Detroit still has a bunch of work to do.

The Lions are still in pursuit of veteran guard Justin Blalock. Scott Cunningham/Getty Images

2.The more I think on it, the more I like the Walker signing. It’s somewhat of a risk for the Lions because his role with the Saints was smaller than the one he’ll likely have with Detroit, but Walker has a ton of potential. The Lions haven’t divulged their plan for Walker or Ngata, but if Walker ends up being the No. 3 tackle in a rotation with Ngata and either a veteran or a high-end rookie, he could thrive. One area Detroit’s front office has been particularly good with is identifying good free agent and waiver claim fits the past two seasons, including Ihedigbo, Glover Quin, Isa Abdul-Quddus, Golden Tate, Reggie Bush and George Johnson. It’s obvious Detroit sees something it really likes.

3.Nick Fairley is in a good place. The former Lions defensive tackle signed a one-year prove-it deal with St. Louis and it is a good spot for him. Much like when he was with the Lions, he will be surrounded by top-end talent and won’t be the player most opponents double team. It was smart by the Rams to put him on a one-year deal because if the Lions showed anything about Fairley, it is when he is motivated, he can play some outstanding football. In his contract year in 2014, he was outstanding until being injured. As far as Detroit, Fairley didn’t have much to say to colleague Nick Wagoner during his meeting with the media Friday. He referred questions about the Lions’ interest to his agent and said he and Suh texted each other “good luck.”

4.The Lions are getting competition for Justin Blalock. As I reported this morning, Blalock had his visit with the Lions and still is garnering interest from St. Louis. Both the Lions and Rams make sense for the 31-year-old guard, and it’ll be interesting to see how long this plays out. Remember, Ihedigbo visited, left and then signed a week later. But if Blalock goes somewhere other than the Lions, that could mean the return of Rob Sims for one more season. For now, this looks like it’ll be a veteran spot for a year with a player to groom.

5.John Harbaugh on Ngata. Colleague Dan Murphy, who covers Michigan and the Big Ten for ESPN.com, went to go hear Harbaugh chat in Ann Arbor, Michigan, on Friday. He was asked about Ngata, who was traded from Baltimore to Detroit on Tuesday.

“First of all a first-class guy. His son is 5 years old and he’s a little mini-me Haloti Ngata, I’ll tell you that right now,” John Harbaugh said. “We see him at practice running in the sprinklers after practice. He gets soaking wet but he looks just like Haloti. We need to get him an offer right away here at Michigan. He’s got a great family, great wife. “As a player he’s a great football player. He’s a run stopper. He’s a powerful inside pass rusher. It would’ve been nice if we had been able to keep him. I tried to. I thought that would happen actually. I thought we’d be able to come to something that would work for both of us financially, but we weren’t able to do that. Certainly no hard feelings. I wish him nothing but the best here in Detroit. We are happy that he’s in the NFC and not the AFC.”

As for the son Harbaugh references, that’s the same son Ngata was picking up from school when Harbaugh called him to tell him he’d be traded.