John Sheridan has demanded his players be more ruthless in front of goal after admitting their scoreless run at home is "worrying".

The Blues have failed to find the net in their last three Brunton Park games, the latest being last night's 1-0 defeat to Grimsby.

That followed previous setbacks against Tranmere and Stevenage, which have contributed to United's slide to 13th in League Two.

Sheridan said: "The lack of goals at home is worrying. We've only scored five at home and five away.

"We should be doing a lot better with what we've got in the team."

Although United had plenty of play and attempts against the Mariners, they were unable to find a way past Michael Jolley's strugglers.

Sheridan said: "We're not ruthless enough. We're untidy when we're up there.

"The players have got to be ruthless with each other. Don't let anything go by, you've got to tell each other you want better from each other.

"If someone's miscontrolled the ball, or not bringing others into play, you must tell him we need better.

"As players, as a group, the players have got to be ruthless with each other. Not me talking before, half-time, after the game - you need it happening on the pitch."

Luke Hendrie's first-half goal decided the game, ending Grimsby's six-game losing run in the league.

Sheridan added: "We're shooting ourselves in the foot.

"This is what League Two is all about.

"I'm looking at two home games really positively, thinking four points, six points, in my own mind.

"But I made it clear to the players they'd be tough games, which they've proved to be.

"In the first half it could have been 3-2 or 2-2, there were chances both sides, and Adam [Collin] has kept us in the game.

"Second half I thought we played really well - we were brave, passed the ball, moved it, everything I wanted to try and get back in the game.

"But the thing we're missing most is scoring goals. We're so untidy from 18 yards. We get in great areas and then someone miscontrols it, someone overhits a pass, someone makes a wrong run…

"We've had 24 shots, I've been told. Not all of them on target but 24 attempts at goal, 64 per cent of the play, we should be winning the game.

"We're letting a good thing go."

Sheridan admitted Grimsby's winner was a "poor goal" from United's perspective.

"Instead of people just standing in areas where they should be defending, people are moving around and chasing," he said.

"I've been a manager at this level for a long time, I don’t get in arguments with the players, I try not to beat myself up. I try and make it as clear as possible what we should be doing better.

"I can analyse as much as I want but at the end of the day we've been beaten again. It's another home game. It's not something I expected to happen. But let me give a bit of credit to Grimsby. I knew they were a good team.

"They're a good footballing side. They showed that in the first half. They gave us problems. I made it clear to the players - everybody's going to be fighting for something in this league.

"It's very frustrating. For you to go anywhere - play-offs, automatic promotion - you've got to win your home games. We've lost the last three and haven't scored a goal at home, and if I look back, performance-wise, possibly we could have scored five or six in the three games, quite easily with the chances.

"But we haven't. When we're in there we've got to be more ruthless, people having a bit of know-how. A bit more cuteness. Anticipate.

"Sometimes the performance is not as bad as the result, if that makes sense. I've got to look and stay focused and positive and believe in them, which I do."

Sheridan, meanwhile, said he would not use United's injuries as an "excuse."

Richie Bennett missed last night's game with a groin injury while Jamie Devitt left the ground on crutches after being substituted following a heavy tackle from Grimsby's Alex Whitmore.

United were also without a substitute goalkeeper with Luke O'Reilly suffering from illness.

"You get injuries, it's all part and parcel of football," Sheridan said. "I'll never make an excuse. I'll try not to. I won't look for one."

On striker Bennett, the manager said: "He's had a scan on his groin, I hope it's not too serious, I don't think it is but we just wait and see.

"I don’t know what happened with Dev. I'll have to see the physio. Obviously he's gone off, I think with a shin injury. We're getting one or two knocks, they're all creeping up."

Sheridan, though, said he would not be able to try and solve United's goals shortage in the market.

United could still sign free agents even though they are outside the loan or permanent transfer windows.

"I won't be bringing anyone in, no," he said.

"Your luck's got to change. We've had 24 attempts at goal. You can't ask for much more. I don’t know how many were on target but we're creating chances and getting in really good areas. It's the end product, we should be doing better."

Sheridan will have Jerry Yates available for Saturday's trip to Oldham with the the forward having completed a two-match suspension.

Mike Jones could also face his former club after making his first appearance last night, as a sub, since the second game of the season.