The Red Devils, losing finalists in last season's FA Cup, will be seeking revenge against the Tricky Trees after they were beaten 2-1 by Nuno Espirito Santo's side in the top flight at the end of December.
Match preview
A week on from claiming three valuable Premier League points in a 2-0 home win over West Ham United, Nottingham Forest were condemned to a 4-2 defeat away against Aston Villa last Saturday.
After Villa raced into a three-goal lead inside the first 39 minutes, Moussa Niakhate and Morgan Gibbs-White netted either side of half time to give the Tricky Trees hope of a comeback. However, Leon Bailey restored Villa's two-goal cushion just after the hour mark, and there was ultimately no way back for Forest, who suffered their 14th league defeat of the season and their fourth top-flight loss since the turn of the year.
Nuno's men remain in the relegation picture as they hover just four points above the drop zone, and without even kicking a ball they have slipped to 17th in the Premier League table this week after Everton's 10-point deduction for financial breaches was reduced to six following an appeal.
Before welcoming leaders Liverpool to the City Ground on Saturday, Forest must first shift their attention to Wednesday's FA Cup tie with Man United as they endeavour to progress to the quarter-finals for the second time in three seasons.
Forest have scraped through to the fifth round this term after requiring replays to beat League One side Blackpool and Championship outfit Bristol City in the previous two rounds, winning 5-3 on penalties against the latter earlier this month.
Although Forest enter Wednesday's clash as underdogs, the Tricky Trees have advanced from four of their previous five FA Cup ties with Man United, while their aforementioned 2-1 home win over the Red Devils in the Premier League almost three months ago should provide Nuno's camp with a boost.
Man United entered last weekend's top-flight clash with Fulham in buoyant mood after putting together a four-game winning run to kick-start February in perfect fashion amidst confirmation of Sir Jim Ratcliffe's 27.7% purchase of the club.
However, just a few days after Ratcliffe vowed to help the Red Devils knock rivals Manchester City and Liverpool "off their perch" at the summit of English football, Erik ten Hag's side suffered a blow in their quest to secure a top-four finish after losing 2-1 to the Cottagers at Old Trafford.
Harry Maguire appeared to have rescued a point for Man United when his 89th-minute equaliser cancelled out an earlier strike from Calvin Bassey, but it was Fulham who had the last laugh as Alex Iwobi netted a dramatic 97th-minute winner to condemn the hosts to their 10th league defeat of the season.
Although Ten Hag heaped praise on his side's "great character" in the loss to Fulham, his side ultimately lacked a cutting edge in the final third; they remain sixth in the table and have slipped eight points behind Aston Villa in fourth spot with 12 games remaining, including a daunting trip to reigning champions Man City on Sunday.
Man United's only realistic hope of silverware this season is the FA Cup, a competition they have won 12 times but not since 2016, despite progressing beyond the fifth round in six of the last seven campaigns.
The Red Devils, who have beaten lower-league duo Wigan Athletic and Newport County to reach the fifth round this term, won 11 games in a row against Nottingham Forest prior to their most recent defeat at the City Ground, and success on Wednesday would see them progress to the FA Cup quarter-finals for a record 48th time.
Nottingham Forest FA Cup form:
D
W
D
W
Nottingham Forest form (all competitions):
L
D
W
L
W
L
Manchester United FA Cup form:
W
W
Manchester United form (all competitions):
W
W
W
W
W
L
Team News
Nottingham Forest trio Ibrahim Sangare, Willy Boly and Ola Aina all picked up unspecified injuries on Africa Cup of Nations duty and there is currently no timeframe on their potential return, while Chris Wood remains out with a hamstring problem.
Nuno Tavares is the latest name to enter the treatment room after he picked up an unspecified injury against West Ham just over a week ago, forcing him to miss the defeat at Aston Villa. Niakhate played a left-back last time out and could keep his spot on Wednesday, although Harry Toffolo is another option at Nuno's disposal.
Divock Origi will be pushing to start up front at the expense of Taiwo Awoniyi, who was only fit to play the first 45 minutes last weekend, and he could be supported in attack by former Man United man Anthony Elanga, as well as Gibbs-White and Callum Hudson-Odoi.
As for Man United, Casemiro has emerged as a major doubt after being forced off with a nasty head injury in last weekend's defeat to Fulham; Scott McTominay, Christian Eriksen or Sofyan Amrabat could deputise in centre-midfield alongside Kobbie Mainoo if the Brazilian is not deemed fit to feature.
The Red Devils will definitely have to cope without Rasmus Hojlund, Luke Shaw (both muscle), Aaron Wan-Bissaka (unspecified), Lisandro Martinez, Tyrell Malacia (both knee), Anthony Martial (groin) and Mason Mount (calf) as they all continue to recover from injury.
After making his first senior start against Fulham, teenage academy graduate Omari Forson will be hoping to retain his place on the right side of attack, although he faces competition from Antony, while Marcus Rashford and Alejandro Garnacho will likely complete the front three.
Nottingham Forest possible starting lineup:
Sels; Montiel, Felipe, Murillo, Niakhate; Danilo, Dominguez; Elanga, Gibbs-White, Hudson-Odoi; Origi
Manchester United possible starting lineup:
Onana; Dalot, Varane, Evans, Lindelof; McTominay, Mainoo; Forson, Fernandes, Garnacho; Rashford
We say: Nottingham Forest 1-2 Manchester United (after extra time)
Although Premier League survival remains the priority for Nottingham Forest, success on Wednesday against a Man United outfit, whom they have already beaten this season, could act as a springboard for a much-needed positive run of form in the coming weeks.
A closely-fought contest may be on the cards at the City Ground, one that could even go beyond the 90 minutes now that replays have been scrapped from this stage onwards, but if the Red Devils can rediscover their spark in attack, they may just do enough to secure their spot in the quarter-finals.