New York Jets coach Rex Ryan was unhappy with his side's performance despite their 19-14 win over the Oakland Raiders on Sunday.
Despite an error-riddled display, the Jets opened their NFL season with a victory thanks to their defensive efforts.
Ryan said plenty of improvement was needed before his team take on the Green Bay Packers on September 14.
"It is still a work in progress and it has to get better for us to do what we want to do," he said.
"But we knew the Raiders were going to come here and push us around and they certainly did that to the tune of 25 yards rushing and they gave up 213 rushing.
"That part of it was Jet football and I am proud of the way we played running the football and the way we stopped their run but we know it has to get better."
Ryan added: "We will take it, not happy with it but it is a victory and I know we have to get better."
The Jets gave up 11 penalties for 105 yards, but linebacker Demario Davis said the officiating was inconsistent.
"I am very proud of the way our defence played today," he said.
"Two things I would change though, firstly the penalties. I am not mad at us. We are an aggressive defence and penalties are going to happen.
"But anytime we are throwing that many penalties on our defence I wish they [referees] would do the same on the other side.
"Secondly, on our defence we didn't get any turnovers and that is a big point of emphasis for us and we have to get those turnovers.
"Other than that I am proud of the way we played and we have got to replicate that every week."