Hopes were high when one manager who had enjoyed a glittering playing career replaced another at Pride Park, but Cocu has so far struggled to live up to the standards set by Frank Lampard during his sole season in charge.
The Dutchman began his reign strongly with a 2-1 win away to newly-relegated Huddersfield Town on the opening day, but Derby are winless in five league games since then.
A 3-0 defeat at Brentford - which also came off the back of losing by the same scoreline at the home of their biggest rivals Nottingham Forest in the EFL Cup earlier in the same week - leaves the Rams 19th in the Championship table, just two points clear of the relegation zone.
By contrast, Lampard's Derby had amassed double the number of points at the same stage of last season, although it remains very early days for Cocu's tenure and he will hope to be given plenty more time to turn things around.
Fans will nevertheless be demanding that some signs of improvement become evident after the international break, having come agonisingly close to being promoted to the Premier League last season.
Cocu's opposite number in the dugout this weekend is a man who knows all about getting teams into the top flight, although Cardiff will also need to show more throughout the remainder of the campaign if they are to mark Neil Warnock's final season in management with a record-breaking promotion.
The Bluebirds go into the match sitting in the bottom half of the table following a mixed start which has seen them win two, draw two and lose two of their six outings so far.
Only one of their eight points has come away from home, but Derby's form at Pride Park also leaves a lot to be desired with only two points and two goals from their three league outings there this season.
Just like Friday's hosts, Cardiff were unceremoniously dumped out of the EFL Cup in the second round courtesy of a 3-0 defeat to Championship opposition, although they did respond better than Derby and went into the break off the back of a 1-1 draw with Fulham.
Derby form: WDLDLL
Cardiff form: WLWDLD
Derby could welcome a number of players back into first-team contention for this match, with Jayden Bogle, Scott Malone and Florian Jozefzoon all having used the international break to work their way back to fitness.
Lee Buchanan, who has started Derby's last three matches, was forced to pull out of international duty having come off at half time against Brentford, although Cocu insists that his hamstring issue is only minor and he could be available this weekend too.
Cardiff, meanwhile, have been boosted by the news that Sol Bamba is closing in on a return having been sidelined since March, although he will play no part in this match and is more likely to return towards the end of the month.
Neil Etheridge, who was one of their standout players in the Premier League last season, is back in full training after tearing his hamstring on the opening day of the season and could even be in contention to replace Alex Smithies in goal against Middlesbrough on September 21.
There is better news in that Nathaniel Mendez-Laing could make his first start since the opening day having come through his return cameo unscathed before the international break.
Derby possible starting lineup:
Roos; Bogle, Keogh, Bielik, Holmes; Knight, Huddlestone, Dowell; Marriott, Waghorn, Lawrence
Cardiff possible starting lineup:
Smithies; Peltier, Morrison, Flint, Bennett; Bacuna, Ralls; Mendez-Laing, Tomlin, Murphy; Glatzel
We say: Derby 1-1 Cardiff
Neither of these sides are in the best form coming into this match and are still adapting to another season in the second tier - Derby after coming so close to promotion and Cardiff following their relegation. Both will have no doubt used the international break to work on what was not necessarily working beforehand, but we can see the two sides cancelling each other out on Friday night.
body check tags ::