With spring officially here, teams are starting to really buckle down on preparation for the NFL Draft. In the same breath, free agency has reached a standstill.

The top remaining guys could sign somewhere tomorrow, next week or while I’m typing this sentence. However, there has been a strong wave of players receiving deals and while we already know about guys such as Malik Jackson, Brock Osweiler, Russell Okung and other top talents, let’s take this time to look at the best underrated acquisitions.

Sean Smith – After finishing the season with a promising (7-9) record, the Oakland Raiders have addressed their weaknesses. Offensively, we know this team has a plethora of talent from Derek Carr to Amari Cooper to Michael Crabtree, but the other side of the ball needs to catch up for Oakland to be considered legit contenders in the AFC.

If an effort to improve defensively, Oakland has signed the likes of Bruce Irvin and Sean Smith.

Smith may not be a true number one guy, but he’s definitely someone who a lot of teams would love to have. This past season, the 28-year-old defended 12 passes and snatched down two interceptions.

Considering his size and athleticism, Smith will prove to be a huge acquisition.

Chase Daniel – Sure, Daniel will probably only be a backup, especially since Sam Bradford is still under contract. Nonetheless, the Eagles could release Bradford in 2017, but they would be taking a $9.5 million hit in dead money.

Although Daniel has been nothing but a career backup, still the former Mizzou product has been under Doug Pederson for a few years now, who is the new head coach of the Eagles.

For now, however, it’s clear who Pederson wants under center.

“Talking about the quarterback situation going forward, Sam Bradford is the No. 1, Chase Daniel is the No. 2, and we’re working on the No. 3,” Pederson stressed. “So I just want to put that out there right now going forward. We feel like – and I feel like as the head football coach of the Philadelphia Eagles – that we’ve really given ourselves a great opportunity at that position.”

While it’s still likely Philly will draft a quarterback to groom under Bradford, don’t rule out the possibility of Daniel getting an opportunity in the near future if Bradford doesn’t meet expectations or if he gets injured again.

Ladarius Green – In the wake of Heath Miller retiring, the Pittsburgh Steelers were in dire need of tight end depth. The only reason Green doesn’t have the numbers you’ll look for is because he hasn’t played much. After all, he did have a guy named Antonio Gates to share targets with for four years.

With that being said, Green delivered for the first four games when Gates was suspended for PED use. The 6-foot-6 pass catcher snatched down 19 catches for 224 yards to go along with two touchdowns during that timeframe.

In Week 5, Pittsburgh traveled to San Diego and while Gates was returning, head coach Mike Tomlin mentioned Green in his assessment of their aerial attack.

“His running mate, Ladarius Green, is a talented vertical threat-like tight end. He is an oversized wide receiver,” Tomlin stated. “He is adept at getting up the field. He has logged a lot of quality reps here in the first four weeks of the season and he has built a nice rapport with Rivers.”

Now, Tomlin can have fun placing Green all over the field.

Ryan Harris –  The Steelers weren’t done with Green.

Future Hall of Fame quarterback Ben Roethlisberger isn’t getting any younger, so protecting him becomes more of a priority as the years fly by, which is why they went out and signed former Denver Broncos offensive tackle Ryan Harris.

Harris was a major key in protecting Peyton Manning throughout Denver’s run and he’s looking to do similar things with Big Ben.

“I see myself as a veteran offensive tackle with dozens of starts and a Super Bowl championship ring that can come in and provide both leadership and talent to an already talented and well-led organization,” Harris said.

Although he wasn’t all that sought after, Harris can man the right side opposite Al Villanueva and they should be able to keep the two-time Super Bowl champion quarterback upright.