EAST RUTHERFORD, N.J. -- In yet another blow to the New York Giants' receiving corps, Golden Tate has been suspended for four games for violating the NFL's policy on performance-enhancing substances, he confirmed Saturday.

Tate, who said the banned substance was a prescribed fertility medication, has scheduled an appeal for Aug. 6 and a resolution is expected before the start of the regular season, league sources told ESPN's Adam Schefter.

In a statement, Tate said he believes he has a legitimate case to win his appeal.

"This past April, during the off-season, my wife and I decided to see a specialist for fertility planning. I started the treatment prescribed to me and just days later I discovered it contained an ingredient that is on the league's banned substance list," Tate said in a statement. "I immediately discontinued use, I reported the situation to the Independent Administrator of the NFL Policy on Performance-Enhancing Substances, and I spoke with my coaches and general manager. I did all of this well before a failed test was even confirmed.

"Per NFL protocol, an initial suspension was imminent, but myself and the Giants organization are confident in the facts, and eagerly await my appeal to put this behind us."

However, according to the NFL's policy on performance-enhancing drugs, it might not be that easy. It states, "Players are responsible for what is in their bodies and a positive test will not be excused because a Player was unaware that he was taking a Prohibited Substance."

The Giants were already down two receivers after Corey Coleman (torn ACL) and Sterling Shepard (fractured thumb) suffered injuries on the first day of training camp on Thursday.

Coleman is likely to miss the entire 2019 season, while Shepard will be evaluated on a week-to-week basis with a possibility of returning in time for the season opener in six weeks.

The Giants have known about Tate's possible suspension for quite some time and haven't made any significant moves at the position over the past few weeks.

"We'll just wait and see what happens with Golden and his appeal," Giants coach Pat Shurmur said Saturday. "You guys saw [Shepard] running around yesterday out there. He's going to be fine. We have other guys that are competing to make our team. So just keep moving."

Tate was the Giants' big offseason acquisition following the trade of Odell Beckham Jr. to the Cleveland Browns. Tate signed a four-year, $37.5 million deal in March after finishing last season with the Philadelphia Eagles.

The veteran wide receiver has spent the bulk of his career with the Seattle Seahawks and Detroit Lions. He has caught 611 career passes for 7,214 yards with 38 touchdowns and made the Pro Bowl his first season with the Lions in 2014.

Tate's transition to the Giants had been rather seamless. He is expected to play a major part in filling the production left behind by Beckham.

Shurmur said Tate's statement spoke for itself, adding, "when this situation arose, he's been very honest with us. It's just getting to the point now where I think he's going to have his appeal."

During the suspension, Tate can continue to practice with the Giants and can play in preseason games.

With the suspension and injuries, the Giants' receiving corps currently is comprised of Cody Latimer, Russell Shepard, Bennie Fowler, Reggie White Jr., Alonzo Russell and rookie Darius Slayton, among others.

Slayton, a fifth-round pick this year, is dealing with a hamstring injury.

The Giants signed Amba Etta-Tawo following a workout Saturday morning, according to his agent David Canter. Etta-Tawo spent last summer with the Giants, and he was on the Giants and Texans' practice squads for parts of last season.

The Giants also signed receiver T.J. Jones, sources told ESPN. He spent the past four seasons with the Lions.

"We'll let the transactions speak for themselves," Shurmur said.

Serious questions still remain about the Giants receiving corps heading into the season.

"That's how we like it. We have nothing to lose," veteran wide receiver Russell Shepard said. "That's what you want. You want people to doubt you at times so you can prove them wrong. You want people to kind of give up on you. That is what this group of guys is going to do. We're going to go out and show why we deserve to be here, why we're going to be here and why we're going to help this team win games come Sunday."

On Friday, Tate had said the wide receivers' room was "deflated" by news of Coleman's injury.

While with the Seattle Seahawks in 2013, Tate was critical of two teammates who received suspensions for substance abuse violations, calling them "selfish."

"You are affecting way more than yourself," Tate told 710 ESPN Radio at the time. "I feel like that was kind of a selfish move on both those guys' part. But it is what it is. The show must go on and that's what we're gonna do."

On Saturday, Tate said the prescribed medication did not provide any "competitive advantage" and that he prided himself for following the league's protocol throughout his 10 seasons.

"During the entirety of my 10 year career, I have taken great pride in playing this game the right way, have been an ambassador for the NFL and have never had any issues with the league's policy," Tate said. "The treatment this past April had no effect on the upcoming season, and I did not, and could not have undergone this treatment in April for any competitive advantage.

"I deeply appreciate the support from the New York Giants Organization, and will continue to hold the highest level of character and integrity, while being a leader in the locker room."