Fantasy Football owners have to start gearing up for Week 2. The first Week of the 2015 NFL season is just about complete, and what a week it was. Playing the waiver wire is extremely critical because so many unexpected things will happen during the season, especially injuries.

Here are five players you should consider signing off the waiver wire for Week 2.

1. Terrance Williams

Terrance Williams is a good underrated wide receiver who had eight touchdown grabs last season, and his stock is about to go way up. Why is that? Star wide receiver Dez Bryant has a broken bone in his foot, and he will be out for at least a month. Williams had 60 yards against the New York Giants, and he will get plenty of more looks going forward from Tony Romo. Williams and the Cowboys face the Philadelphia Eagles next week, who ranked 28th in pass defense last season. If you had Bryant or need wide receiver help, Williams could be your guy.

2. Marcus Mariota

What a performance Marcus Mariota had in Week 1 against the Tampa Bay Buccaneers. Was it a fluke or a sign of things to come? Mariota had a perfect 158.3 passer rating completing 13 of 16 passes with four touchdowns and zero interceptions. More than likely you don't have Mariota on your team, but if you need quarterback help for Week 2, it might be wise to grab him off waivers. Mariota is currently owned by less than 20 percent of Fantasy Football owners. Mariota and the Tennessee Titans will play the Cleveland Browns next week.

3. Lance Dunbar

Dallas Cowboys running back Lance Dunbar had probably the most underrated Week 1 performance of any player. Dunbar didn't have a single rushing yard, but he made up for it in the air with big catches and critical first downs. With 70 receiving yards on Monday Night, Dunbar was the leading receiver in the game. He also had the most receptions in the game with eight. Romo appears to have good chemistry with Dunbar on short passes, which should set up good against the Eagles next week, especially considering Bryant will not be playing. There's a really good chance Dunbar will be available in your Fantasy Football league.

4. James Jones

James Jones played for the Green Bay Packers from 2007 to 2013, and for the Oakland Raiders last year, but it was like he never left. Jones played big for the Packers on Sunday catching two touchdowns in a win over the Chicago Bears on the road. Jordy Nelson is out for the season, so you can bet Jones will get plenty of balls thrown his way going forward from Aaron Rodgers. The Packers take on the Seattle Seahawks at Lambeau Field on Sunday Night Football in Week 2.

5. Travis Kelce

The Kansas City Chiefs were big winners in a Week 1 victory over the Houston Texans, and they have a huge game against the Denver Broncos and Peyton Manning on Thursday Night Football. Alex Smith still hasn't thrown a touchdown pass to a wide receiver, so you better grab tight end Travis Kelce while you can. Kelce had a monster game in Week 1 with 106 receiving yards and two touchdown grabs. Last season Kelce emerged as one of the most productive tight ends in the league with 862 receiving yards. With Smith throwing a wide majority of his passes below the 10-yard mark, Kelce is a lock to start in Week 2.

 Follow Damon Salvadore on Twitter @DamonSalvadore1