TEMPE, Ariz. -- Usually even-keeled, Arizona Cardinals rookie wide receiver Marvin Harrison Jr. said Wednesday he found himself getting frustrated during Sunday's loss to the Buffalo Bills at Highmark Stadium.

The No. 4 pick had only one catch for four yards on three targets in his NFL debut, but Harrison said his frustration was largely geared toward how the game was unfolding -- his NFL debut not panning out how he had hoped.

"I mean, obviously it wasn't great," Harrison said. "Definitely wasn't what I expected, what I wanted to happen, what the team wanted to happen. Obviously, you wanted to come out with a victory and we didn't do that."

Harrison added he felt as if he could have done a better job of helping Arizona win.

"That's why it kind of brought me here is to help the team, help the offense go," he said. "So, I have to do a better job of that going forward.

"I got to get open and catch the ball. That's my job as a receiver. That is your job description. That's what I got to do a better job."

The Bills tried to take Harrison out of the game by using a cloud coverage, which is when a corner rolls up to jam and reroute Harrison. It was his first time facing NFL defenses beyond three snaps in the first preseason game against the New Orleans Saints.

Harrison didn't play the rest of the game against the Saints or the last two preseason games and he said it prevented him from playing free Sunday.

"Thinking a lot," Harrison said. "I was definitely thinking a lot out there and I think that'll come with reps, thinking less and just going out there and playing. It'll definitely come with reps and it's something I'll get better at, but I definitely say I was thinking a lot out there."

Quarterback Kyler Murray said "nothing changes" with his communication to Harrison after Sunday's showing.

"We have the utmost confidence in what we're capable of," Murray said. "If you went back and watched the game, I think they were doing a good job of making sure that he wasn't going to be singled up or not be singled up for the majority of the game.

"I'll never lose confidence in Marv. It was his first game. We have to continue to get better and we will."

Harrison and Murray spent time over the past couple of days watching the film and talking through certain situations. Murray asked Harrison what he saw on certain plays, and they discussed how it played out.

Harrison hopes his connection with Murray develops "sooner rather than later," but doesn't think they're in a "bad place." Live reps, Harrison said, will help their on-field relationship.

"Obviously, we want to get him more touches," Murray said. "That's not a secret, but I don't want to go forcing things for sure."