We are now four weeks into the season and certain players are starting to emerge as legitimate fantasy threats. Calvin Ridley followed up his 3 touchdown day by scoring another two against the Bengals on Sunday. Tyler Boyd followed up his week 3 with 11 catches for 100 yards. Dede Westbrook, who headlined this article last week [VIDEO], had nine catches for 130 receiving yards and ended his day with 12 fantasy points. Which players from the waiver wire are worth adding for week 5?

1. Chicago Bears WR Taylor Gabriel (6.1 % Ownership)

Did anybody see Mitchell Trubisky's six touchdown day coming? Trubisky shredded the Bucs defense, and Gabriel was a major beneficiary.

He ended his day with seven catches for 104 yards and two touchdowns. At this point, the Bears are clearly committed to getting Gabriel involved, and he should have some fantasy value moving forward.

2. Seattle Seahawks RB Mike Davis (0.0 % Ownership)

Mike Davis went from complete irrelevance to potential fantasy starter in just one game. Davis rushed for over 100 rushing yards and had two touchdowns, accounting for a majority of Seattle's offense. Even if Carson comes back, Davis may have earned the starting running back role with his performance.

3. Jacksonville Jaguars WR Dede Westbrook (12.6 % Ownership)

Fantasy owners who didn't pick up Westbrook last week [VIDEO] missed out on a 12 point fantasy day without a touchdown. Bortles seems to consider Westbrook to be his top receiver, which gives him fantasy value moving forward.

The only question is how many catches and targets Keelan Cole and Donte Moncrief steal from the talented wide receiver. In any case, it is worth adding Westbrook from the waiver wire.

4. Cincinnati Bengals TE Tyler Kroft (0.4 % Ownership)

Tyler Eifert was playing well and had a touchdown prior to his injury in the third quarter against the Falcons. Unfortunately, Eifert was carted off the field from that injury and he probably won't be returning anytime soon. That opens the door for Kroft to take on a bigger role as Dalton's main tight end. Kroft is worth adding from the waiver wire for fantasy owners in need of a tight end.

5. Tennessee Titans QB Marcus Mariota (20.3 % Ownership)

The Titans quarterback finally returned to relevance with a 29-point fantasy performance against a tough Philadelphia Eagles defense at home. Mariota's rushing ability makes him a scarier fantasy threat, and he has a great matchup next week against a Buffalo team that allows opposing offenses to rack up possessions. Mariota is worth an add from the waiver wire, especially with several bye weeks coming up.