Sammie Cotes was a weapon last September but not much more than a memory by the time the 2016 season ended.

The lesson learned is one Coates has vowed not to forget.

"At the end of the day, it's all mental," Coates said.

Especially when you're trying to play at less than 100 percent.

Coates attempted to do that after suffering a broken finger on Oct. 9 against the New York Jets and another on Nov. 6 at Baltimore.

He caught 19 passes for 421 yards and two touchdowns through the first five games, including six receptions for 139 yards and both of his scores (one a 72-yard touchdown reception) against the Jets.   

But over the final 11 regular-season games Coates managed just two catches for 14 yards (he was inactive on Dec. 25 against Baltimore and didn't play on Jan. 1 against Cleveland).

Coates appeared in all three of the Steelers' playoff games and emerged from the postseason with two receptions for 34 yards (both in the AFC Championship Game against New England).

"You have to be able to not let it get in your head," he said. "Once you have one bad game, it kinda becomes a domino effect. You start letting it add on to the next game, the next game.

"I started thinking more about my fingers instead of just playing football. That stuff happens, I have to learn from that."

Coates said he received plenty of support as he tried to effectively play through his injuries.

"Coach Mann (wide receivers coach Richard), 'A.B.' (Antonio Brown), they were telling me 'you're going to be good,'" he said. "It happens to players all the time. You just have to learn how to deal with it. 'D.H.B.' (Darrius Heyward-Bey), the whole (wide receivers) room helped me stay up and keep me in the game."

It wasn't enough.

"Mentally, it just broke me down," he said. "I started out so hot, and then you're not the same player anymore. At the end of the day, you can't let that happen to yourself."

Coates maintained he learned from the experience and he'll be better for it.

"I'm growing as a player every day," he said.

The Steelers have grown at wide receiver since last season via the conditional reinstatement of Martavis Bryant from indefinite suspension and the drafting of JuJu Smith-Schuster on the second round.

"It's football, it's competition," Coates observed. "You have a room like that, a bunch of guys can go anywhere and be a starter, it's going to be fun competition coming to (training) camp.

"Right now everybody's learning. When camp comes it's going to be competition, make each other get better."