The Buffalo Bills had a nice regular season, but a terrible collapse during their Wild Card game against the Houston Texans threw them into offseason mode quicker than they were hoping for.

The Bills have a good base, but there are still some major holes they need to be filled. Let's breakdown the three biggest needs the Bills should be focusing on this offseason.

3. Defensive line

All signs are pointing towards the Bills losing Shaq Lawson and Jordan Phillips entering the free-agent market, which could be major losses for them. Rookie Darryl Johnson showed some flashes of being a solid defensive end, but they still need more. The Bills are going to have plenty of cap space, and some of that needs to be spent on the line.

For the Bills, this isn't the type of situation where they need to drop $50 or $60 million on a star, but they need some solid guys who can fill in. They might not even need to be starters — bringing in solid rotational guys that could be starters if injuries arose could be enough.

The one thing the team can't do is think the defensive line is good enough and not bring in anyone to help improve the pass-rushing and run-stuffing units.

2. A second running back

The Bills hit the jackpot with Devin Singletary, but with as much as the Bills like to run the ball, it would make a lot of sense for the team to find a second running back for a one-two punch.

Frank Gore was fine, but they need to find someone that is an upgrade. Bringing in someone like Kareem Hunt, Carlos Hyde, or even Melvin Gordon would be a big upgrade.

Gordon might want too much money for the role he would have with the Bills, but he would be a perfect addition to the backfield.

1. Star wide receiver

The Bills brought in Cole Beasley and John Brown in the last offseason. Both guys were big impact players on the team. Those were two quality pieces that will help the team going forward, but now the team needs to go and get that one true impact wide receiver. Going through the draft would be fine, but they should be trying to go through free agency or the trade market to find that guy.

A.J. Green, Emmanuel Sanders, or Amari Cooper are all players that the Bills should be trying to go after. If they can't land one, it would make sense to try and make a trade for a star receiver.