Mowbray sees signs to encourage him

“I think result-wise it was a bad day at the office, we conceded some bad goals,” he said.

“We need to be a bit more clinical in both boxes. There were some good signs for our team, but it’s a new team built over the summer. We’ll get better I’m sure.

“I thought the defence were fine. We’ve had some injuries, but as you move along you hope to get a consistent back four that has an understanding but that hasn’t been the case in the first four games for us.

“Hopefully we’ll find the right balance as we go along. You can’t lose the type of goals that we did and expect to come to Millwall and win.

“I would like to think we’re going to challenge. We’re a club with ambitions to get back to the Premier League. We have to punch above our weight as Blackpool have done recently.”

Keogh, who joined from Wolves in January, scored in both halves after Liam Trotter had given the Lions an early lead, with Marvin Emnes’s penalty after 43 minutes Boro’s only response.

The goals were Keogh’s first of the new season after he finished the last campaign with five in his final seven games to secure Millwall’s Championship place.

Trotter fired the Lions ahead in the 25th minute after collecting a flick from James Henry, who 10 minutes later struck a post and Keogh pounced from the rebound.

Emnes, who stayed with Boro despite reported interest from Swansea City, gave his side hope when he converted a penalty two minutes before the break, but Keogh sealed the win after 86 minutes to leave visiting manager Mowbray admitting there is work to do.

Millwall: Maik Taylor, Dunne, Osborne, Lowry, Malone, Henry (Feeney 83), Trotter, Wright, Abdou, Keogh, Henderson (Batt 46). Unused substitutes: Forde, Shittu, Racon, Marquis, Chris Taylor.

Middlesbrough: Steele, Hoyte, Woodgate, Hines, Friend, Zemmama (Ledesma 55), McEachran, Leadbitter, Haroun (Smallwood 62), Miller (Luke Williams 73), Emnes. Unused substitutes: Ripley, McManus, Arca, Reach.

Referee: Fred Graham (Essex).

Man of the match: Andy Keogh.