Leicester City boss Nigel Pearson has threatened to make changes after his side's 3-2 Championship defeat at Watford left them with an uphill battle to force their way into the play-off places.

The Foxes take on Norwich City in the FA Cup fifth round at Carrow Road on Saturday, looking to bounce back from what the manager described as an 'unacceptable' showing at Vicarage Road on Tuesday night.

'It was a game we should have won, but we started that poorly and were that lacklustre in certain areas, I'll be looking to make changes,' said Pearson, frustrated by his team's sloppy defending.

He said: 'We need to be better and more efficient and more consistent – simple as that.

'The goals that we conceded were poor goals. We didn't start the game well enough, scored two exceptionally good goals and that should be enough to win the game but we've made some poor decisions on the night and it's cost us dearly.'

Two goals in seven first-half minutes from David Nugent gave Leicester a 2-1 advantage at one stage, but defeat ultimately left Leicester nine points off the Championship's top six.

Said Pearson: 'We knew what to expect, you've just got to deal with it, simple as that.

'When you score two goals away from home – two super goals as well, by the way – it's frustrating. I'd have been disappointed to have drawn that game.

'I am not happy with certain aspects of our performance and the main disappointment is that what's improved our performances of late was missing in the initial period of the game.

'That's something I'm not prepared to accept.

'I've been very patient so far in terms of how to change it.

'My responsibility is to put it right and I will do.

'There are aspects of our game tonight that I will change.'

Pearson warned: 'I've just told the players that I don't want to hear anybody talking about the season being over.

'It doesn't enter my mindset as far as I'm concerned and I don't expect anybody else within our ranks to be talking in those terms as well.

'We have to wait a bit longer before the next league game, which is a frustration, but we have a cup game coming up now which gives me an opportunity to maybe look at one or two different options.'

Leicester have yet to concede a goal in the FA Cup, beating Nottingham Forest 4-0 in a replay after a goalless draw, and winning 2-0 at home to Swindon in round four.

Pearson admits they will be seen as underdogs at Carrow Road, and a better performance is essential.

'We need to firstly get the performance in the fashion we all expect and I would say that the players would agree with that,' he said.