OXFORD United’s first-half performance was their undoing at Lincoln City, says Karl Robinson.

The U’s were second best before the break at Sincil Bank, although the Imps did not take the lead until Anthony Scully’s 40th-minute strike.

Lincoln debutant Morgan Whittaker made it 2-0 shortly after half-time as United missed the chance to go third in Sky Bet League One.

Read the match report here

The U’s were hampered by an injury to Cameron Brannagan in the build-up to the opener and Herbie Kane’s late red card for a challenge on Lewis Fiorini.

But Robinson felt his side’s first-half display left them with no excuses.

United’s head coach said: “The first half was a long way off what we believe is right.

“You can’t come here and perform the way we did in the first half and expect to get anything out of the game.

“Some of our decision-making was poor and our technique let us down in the final third.

“Everything about the first half was wrong, I thought we deserved to win the second half.

“I thought we were much better, we were collectively closer and we made it much more difficult for the opposition.

“This is a disappointing afternoon – don’t let anywhere think this is going to sit well with any of us.

“This really hurts, we apologise to the fans who made the trip. We’ve got to do better, it’s that simple.”

Both sides put in plenty of feisty challenges throughout the contest, yet referee Sebastian Stockbridge did not produce a card until Kane’s 77th-minute sending-off.

Robinson thought the official should have gone to his book earlier, noting one flying challenge from Lincoln captain Conor McGrandles.

He said: “McGrandles’ tackle in the first half is one of the worst tackles we’ve seen. He made some tackles going through players.

“Herbie pulls out at the end, his foot comes high because of where he pulls out.

“I’m not going to take anything away from them, they deserved to win the game.”

The U’s head coach was non-committal on whether they would appeal Kane’s dismissal, with straight red cards often punished by a three-match ban.

He added: “I can see why he’s done it (sent Kane off), the rose-tinted glasses have to come off sometimes.

“When you see what’s also gone in that’s not been deemed a yellow, that’s the bit that makes me sceptical of why.

“It’s like when the guy said Sykesy (Mark Sykes) headbutted him, or Mags (Chris Maguire) stamped on him.

“I don’t think some of that’s correct, but it is what it is.

“The big thing for me is not what the referee did, it’s the 45 minutes in the first half. That’s the thing we have to be better at.”

Robinson also confirmed that United did not yet know the full extent of Brannagan’s injury.

He said: “It's the top of his hamstring and the bottom of his glute, we’re still not 100 per cent sure.

“He’s a little bit stiff in that area so we’re not going to take any risks.”