Defeat in south London, thanks to Jed Wallace's thumping strike, kept them three points adrift of safety, raising the stakes of their Easter Monday clash with fellow strugglers Wycombe even higher.

Warne said: "I think it was a good save, I don't think it was a horrendous penalty, but unfortunately it didn't go in the corner enough, like Jed's shot did.

"There's no complaint from me – you've got to have some bravery to take a penalty and it would have been fitting for the lad's work ethic today.

"To come away with a point here would have been a great point.

"It was a competitive game, where both teams cancelled themselves out for large periods.

"I thought Millwall started better than us and then we came into it – I thought we nicked it a bit, first half, and I thought we should have had a penalty, but then I would.

"In the second half, it was a fair sending-off [for Richard Wood], I've no complaints, it was a brilliant goal from Jed Wallace, an absolute top-bag screamer, which unfortunately was in a position the keeper couldn't get."

Rotherham's Michael Ihiekwe was the closest to scoring in a poor first half when his header from Daniel Barlaser's free-kick was brilliantly saved by Bialkowski.

But things took a turn for the worse for the Millers when they lost their captain Wood to a red card in the 56th minute for hauling down Wallace when he was the last man.

Viktor Johansson did well to keep out Danny McNamara's effort a minute later, but he could do nothing about Wallace's thunderbolt into the top corner in the 64th minute, following an over-hit Scott Malone corner.

Despite being a man light, Rotherham finished the stronger and were given a penalty late on when Jake Cooper felled Smith from behind, only for the front man's spot-kick to be repelled by Bialkowski.

Millwall boss Gary Rowett thought his side rode their luck.

He said: "We were fortunate, or indebted to our goalkeeper for making a great save.

"I felt the game should have been out the way, in some ways, by that point – we've had a couple of good opportunities, their keeper's made some great saves.

"Jed's finish to put us 1-0 up was a lovely goal and a goal well worthy of winning any game, but Rotherham don't give up.

"They refuse to be ruled out and they keep trying to do the right thing and, with 10 men, I just felt we could have made the game a lot easier for ourselves.

"They forced a penalty – at first, I wasn't quite sure what on earth he had given it for, but it was a great save from Bart that gets us the points."