With the January transfer window entering its final few days, teams across the EFL will be scrambling to ensure that they have a capable squad ready for the remainder of the season.
Cardiff boss Steve Morison will be without talisman Kieffer Moore who has not yet recovered from both injury and illness, as a potential move away looms large. Meanwhile, fellow forward Max Watters could be handed a start after coming off the bench to score in their last game.
In the other camp, Forest manager Steve Cooper remains without youngster Alex Mighten, although he is close to a return from a knee injury. Joe Worrall and Joe Lolley are the only other long-term absentees, with both due to be out for another few weeks at least.
(3-5-2) Smithies, McGuinness, Flint, Nelson, Drameh, Wintle, Pack, Ralls, Ng, Watters, Collins
(4-2-3-1) Samba, Spence, Cook, McKenna, Colback, Yates, Garner, Johnson, Zinckernagel, Grabban, Davis
Cardiff come into the game off the back of a disappointing defeat to local rivals Bristol City last weekend. Despite leading through James Collins, a Chris Martin brace and a goal from Andreas Weimann ultimately saw them fall to their fourth defeat in their last six league games. The other two matches in that run were draws, meaning they are without a win in the league since triumphing away at Luton Town in November. This poor run of form sees them sat in 20th, just three points above the relegation zone. Meaning results need to improve sooner rather than later.
Meanwhile, Forest are heading in the other direction, having won twice in the last week. A 2-1 victory over a troubled Derby County side gave them local bragging rights last Saturday, which was then followed by a comfortable 3-0 dispatching of bottom of the table Barnsley in midweek. Those results helped to make it four wins out of four in all competitions since the turn of the year, which they will hope to continue on Sunday when they cross the border. A win against City could see them end the weekend in the play-off places, adding that extra incentive ahead of the tie.
Ones to watch
Central midfielder Ralls has been a vital player for the Bluebirds ever since he broke into the first-team in 2014, having made well over 250 appearances since then. He has featured 17 times this campaign, bagging five assists in the process, which makes him the most creative player currently at the club. This means Morrison will likely be relying on him to add to that tally between now and the end of the season, in order to boost their survival hopes. The former Yeovil Town loanee has been with the club for 12 years, so will want to help keep them up on a personal level as well.
It has been an exceptional season so far for young Johnson, who has cemented his place in the first team with a number of brilliant performances. The son of former Forest player David Johnson spent last season on loan at Lincoln City, scoring an impressive 13 goals as the Imps came within 90 minutes of promotion. And that is form that he has carried into this season, managing seven goals and six assists so far, giving him the most goal contributions of any under-21 player in the top four tiers.
This has resulted in interest from Premier League clubs, with Brentford making a reported £18 million bid this week, but Forest are keen to keep ahold of the attacking midfielder as they push for promotion.
These sides met on ten occasions in the league between 2013 and 2019, with Cardiff amazingly winning nine and drawing the other. But Forest have had better luck since then, winning three out of five meetings. The reverse fixture back in September was won by the Welsh side thanks to a brace from teenager Rubin Colwill, a result which lifted them up to eighth and left the Midlands outfit bottom with one point from six games.
Their seasons went in very different directions from then on however, meaning City are very much the underdogs this time around. Just one draw in their last 20 clashes means that this also promises to be an all or nothing match.
How to watch
For fans that can't attend the game in Cardiff, the match will be available to watch on Sky Sports Main Event at 16:00 (GMT) on Sunday. With the highlights up by the end of the day at the latest.
What the managers have said
Cardiff manager Steve Morison spoke to the club's media ahead of the game, highlighting the importance of the return of fans to the stadium. He said:
"Hopefully it can make a huge difference. It's always great to play in front of your fans.
"We're really looking forward to the game. It's a big game and a big occasion, fans back and live on Sky.
"Hopefully it'll be a good afternoon."
In the other dugout Forest boss Steve Cooper looked ahead to Sunday's game with the local media, wanting to forget about his sides current form and treat Cardiff like any other game. He said:
"I just want them to play well in every single game.
"I always say whatever has happened in the last game is gone. My expectations for the next game will always be higher in how we play and the result that we get.
"However we played in the last game doesn't change what I want from the next game."