Phillip Cocu believes Derby County’s players will need to ‘really step up’ in what he fully expects to be a difficult Emirates FA Cup Fourth Round tie at Northampton Town tonight (8pm kick-off).

Derby will take on the Cobblers knowing that a victory will see them reach the Fifth Round of the competition for the second season in succession.

Northampton are flying high in Sky Bet League 2 under the management of Keith Curle and they sit sixth in the table.

Cocu has no doubt that the Rams have been handed a tough test against a side that, on home turf, will be looking to pull off a cup upset against higher league opposition.

Both Derby and Northampton saw off higher league opponents in the Third Round to set up tonight’s meeting.

The Rams overcame Premier League Crystal Palace 1-0 at Selhurst Park earlier this month, while the Cobblers were 4-2 winners at League 1 Burton Albion.

Speaking to RamsTV ahead of the game, Cocu commented: “We don’t have a doubt that their motivation will be sky high.

“That is normal. We have to prepare for it and it will definitely be a difficult game.

“The game style that they play is quite tricky and not easy to play against, so we have to really step up and show we have ambition to go on in the tournament.

“We will push hard to get the positive result that we all want. Northampton are doing well in their league, they will feel good to play a big game against us so it will be difficult.”

He added: “We want to keep the momentum we’ve built up because everyone feels better with a positive energy in training, in games and everywhere.

“If you work hard to get it then you have to make sure you keep it. That is one more reason to give an excellent performance in this game.”

Cocu has stressed that Derby’s preparation for the cup clash hasn’t been any different this week.

He says his side must be fully prepared, regardless of the division their opponents play in.

The Dutchman has also made it clear his players must display the right spirit and mentality, which he feels will be an important part of the Fourth Round tie.

He said: “We will prepare the players verbally, but also with clips we will show them how Northampton can play and in the last game in the cup it was a good result.

“We have to prepare like we do for any other game. It doesn’t matter if it is a Premier League club, Championship, League One or League Two; we have to be prepared.

“Then it is about the form you have on the day, how you succeed in the game plan and also show the right spirit and mentality. That will be an important part of the game.”

Cocu has indicated he could shuffle his pack for the clash with the Cobblers.

Derby face a busy few days next week, heading to Luton Town on Tuesday evening before taking on Stoke City at Pride Park Stadium on Friday night.

Cocu made nine changes for the Third Round win at Crystal Palace and, despite keeping his cards close to chest, he says has suggested he may utilise his squad once again.

He said: “There could be some changes. We have played a lot of games and have more coming up, but we also have a lot of players who are doing well.

“There are moments when players need to come back and play games, like we had with Tom Huddlestone at Crystal Palace in the Third Round.

“If you are part of the first team, you have to be able to start games and to play if you are needed. I don’t know how many changes we’ll make, but a few could be possible.”