By Matt Citak

(CBS Boston/CBS Local)The calendar has finally flipped to September, which means that after a long seven months of waiting, the NFL is officially back.

The 2019 season kicks off on Thursday night with the Green Bay Packers traveling to Chicago to take on the Bears at Soldier Field. While this NFC North matchup between Aaron Rodgers and Khalil Mack is a tantalizing battle to start the season, Thursday’s game is even more exciting because of what it represents.

The return of fantasy football.

By now, most leagues have finished their drafts and the rosters are set. However, a lot has changed over the last few days with NFL rosters getting down to 53 players. There are likely some players sitting on your league’s waiver wire whose value increased due to these roster moves, and now deserve a spot on your team.

With that said, let’s jump right into it. Here are the top waiver wire adds heading into Week 1.

RB Devin Singletary, Buffalo Bills

A few days ago, the Bills’ backfield looked rather crowded with Singletary, LeSean McCoy, Frank Gore and T.J. Yeldon all on the roster. However, following McCoy’s release, things seem a lot clearer in Buffalo.

The Bills used the 74th overall pick in April’s draft to select Singletary, and it now appears as if the rookie out of Florida Atlantic will lead Buffalo’s backfield in Week 1. Yes, Gore and Yeldon will still garner some touches early on, but if you have an opportunity to snag a likely lead back on the waiver wire at this time of the year, you do it and don’t think twice.

If Singletary is somehow still available in your league, grab him immediately. If he’s gone and you’re in need of a running back, the ageless Gore could also be worth a look, as he may end up receiving most of the Bills’ goal-line carries this season.

RB Justin Jackson, Los Angeles Chargers

Let me preface this by saying if Melvin Gordon were to return to the team at any point, Jackson’s fantasy value would all but vanish. But at the time of this writing, Gordon is still away from the team, which means Jackson is certainly worth taking a chance on.

Austin Ekeler is owned in just about all fantasy leagues, and for good reason. The third-year back provided fantasy owners with some value even when Gordon was playing last season, and when he was injured, Ekeler took over as the team’s lead back. However, early reports out of Los Angeles indicate that while Gordon is absent this year, Ekeler and Jackson could be used in more of a 50-50 split.

The Chargers offense should once again be dominant this season. Jackson could be looking at double-digit touches each week while Gordon holds out, and if anything were to happen to Ekeler, the sophomore running back would take over Los Angeles’ backfield. He’s worth a speculative add.

RB Carlos Hyde, Houston Texans

Hyde did not look good last season. The veteran averaged a mere 3.3 yards per carry in 2018, and although he signed with Kansas City in the offseason, it was clear towards the end of training camp that he was not going to be there for long.

From a fantasy perspective, the trade to Houston could not have helped his value more. After Lamar Miller tore his ACL in the preseason, it looked like the Texans might roll with Duke Johnson Jr. as their lead back. As promising as he’s looked at times, Johnson has never carried the ball more than 104 times in a season while in the NFL. Hyde has an opportunity now to immediately split carries with Johnson, as the Texans don’t have much depth at all behind the two veterans.

Even though he hasn’t topped 4.0 yards per carry since 2016, Hyde could easily get double-digit touches in a Texans offense that features Deshaun Watson and DeAndre Hopkins, and also just recently traded for left tackle Laremy Tunsil. You could do a lot worse than the soon-to-be 29-year-old Hyde.

WR Deebo Samuel, San Francisco 49ers

As you can tell by the first three names on this list, fantasy football is all about opportunity. Heading into Week 1, Samuel, the 49ers’ second-round pick out of South Carolina, looks like he will get a great opportunity to shine in his rookie season.

The 49ers are currently dealing with some injuries at wide receiver, as both Trent Taylor and Jalen Hurd are banged up. Combine that with the release of veteran Jordan Matthews, and it is clear that Samuel will enter the season as the team’s number three receiver behind Dante Pettis and Marquise Goodwin.

Samuel showed his big-play ability during the preseason, picking up six catches for 104 yards and two runs for 59 yards. If Kyle Shanahan can get Jimmy Garoppolo and the 49ers offense going, Samuel could end up being one of fantasy’s big surprises this year.

WR D.K. Metcalf, Seattle Seahawks

Metcalf recently underwent minor knee surgery, and although head coach Pete Carroll expressed optimism that the rookie receiver could be back on the field for Week 1, there is certainly the chance that Metcalf misses the first week or two of the season. But once he does return to the field, Metcalf will enter a solid situation.

It looked like Metcalf was going to be in a prime position for a breakout this year after the Seahawks surprisingly cut Jaron Brown over the weekend. Seattle brought Brown back on-board Monday, but the rookie should still be able to win the number two receiver job opposite Tyler Lockett. When he does, Metcalf could easily become Russell Wilson’s go-to target in the red zone.

Carroll praised Metcalf’s performance in training camp prior to the surgery. The rookie will have some making up to do once he’s back on the field, but it shouldn’t take long for Metcalf to play his way into the starting lineup. Even in Seattle’s run-heavy offense, Metcalf has an opportunity to surprise a lot of people this year, and prove to the rest of the league that they made a mistake allowing him to drop all the way down to the 64th pick in April’s draft.

Matt Citak is a contributing writer for CBS Local. Follow him on Twitter here for all things fantasy football, New York Giants and more.