Pittsburgh Steelers head coach Mike Tomlin has hit out at his "undisciplined" side following their last-gasp defeat to the Tampa Bay Buccaneers.

The Buccaneers snatched victory with just seven seconds remaining at Heinz Field as Mike Glennon found Vincent Jackson in the endzone, leaving Tomlin to rue his side's defending and the 13 penalties for 125 yards that his team conceded.

Tomlin told reporters: "They did what was necessary to win the game. But after a performance like that, I think it's appropriate that we look within and look at what it is that we are doing.

"The bottom line is that we are an undisciplined group. We are too highly penalised. Obviously, we are not coaching it. We are allowing it to happen. So I take responsibility for that.

"We are not going to win close football games being penalised in the manner in which we've been penalised over the first month of the season. It's unacceptable. It's inexcusable."

The Steelers are 2-2 in their season following their week four defeat.