Manchester United must beat Manchester City on Sunday if they want to keep their title hopes alive, according to Andrei Kanchelskis.
The Premier League's top two go head-to-head at Old Trafford in a pre-Christmas fixture that is about much more than just local pride.
City already sit eight points clear at the summit and a win over their neighbours would leave United with a mammoth deficit to make up, even with 22 games still to play in the campaign.
Kanchelskis - who played for both clubs during his playing career - feels Jose Mourinho's side simply cannot afford to lose further ground in their bid to be crowned champions for the first time since 2013.
"If Manchester United wins this derby game against Manchester City, they've a good chance to win the title," the former Russia winger told Omnisport, speaking at the signing of his book Russian Winters: The Story of Andrei Kanchelskis (deCoubertin).
"It's a must-win game. They [United] need the three points.
"It's a difficult few months over Christmas time, through December and January. There are too many games.
"There is the Champions League, the Premier League, the FA Cup, League Cup and possibly national team duties as well. That's too many, but we will see what happens.
"It [the derby] is important for both teams. If City drop points, there's a good chance for United in this race to be crowned champions. If they don't, it's difficult for United to win the title."
The derby sees Mourinho once again come up against Pep Guardiola, with the pair having previously locked horns at domestic level when they were in charge of Real Madrid and Barcelona respectively.
Kanchelskis admits Guardiola has City firing on all cylinders this season, yet believes this weekend's clash will help settle the argument over who is the better manager.
"Manchester City are playing good football. They are more attacking and have a lot of goal scorers," he added.
"But we will see in December who is best – Mourinho or Guardiola."
|Oxlade-Chamberlain targeting early return|
|New Zealand-born Aki will ´relish´ facing All Blacks – Marmion|
|Portugal cannot focus on absent Ronaldo - Santos|
|Ramsey reiterates he wants to stay with Jaguars despite cryptic tweet|
|We tried to hit a home run and it didn´t work out - D´Antoni explains Carmelo exit|
|West Ham´s Zabaleta backs Premier League´s VAR introduction|
|Southgate eyes winning end to England´s ´brilliant year´|
|Patient Zverev seizes opportunity to make amends at ATP Finals|
|Rodgers: Packers still believe they can make playoffs|
|Mahomes hoping to ketchup to Heinz´s touchdown target|
|Ranieri tells Fulham fans not to expect repeat of Leicester ´fairytale´|
|Brown to leave role as RFU chief executive|
|Croatia star Rakitic ruled out of England clash|
|Capital gains for Zverev as he secures last-four spot in London|
|Sancho rise continues with Player of the Month award|
|Jones-Buchanan, Ablett and Briscoe sign new Rhinos deals|
|Root leads from the front as aggressive England assume control|
|Croatia´s Lovren antagonises Ramos and ´rude´ Spain|
|Rakitic has ´enormous respect´ for England ahead of Nations League decider|
|Ireland make flanker switch with Leavy out of All Blacks clash|
|Pakistan rip through Black Caps in Abu Dhabi|
|WATCH: Barcelona mark 15-year anniversary of Messi´s first match|
|Sterling, that you? - Walker uses falling fan to poke fun at England team-mate|
|Fleetwood applies pressure on Molinari, Wallace leads in Dubai|
|Don´t talk to me about VAR – Rakitic not over World Cup final loss|
|Van Dijk leadership essential for Liverpool – Wijnaldum|
|Dalic: Croatia´s bench was ready to stop Spain!|
|Sublime Root century gives England imposing lead|
|Vinicius appreciates Solari influence at Real Madrid|
|Havertz would suit Bayern Munich – Kimmich|
|Wilder: Roach recruitment a sign of Fury nerves|
|Ranieri targets defensive improvements at failing Fulham|
|PSG close investigation into player recruitment practices after finding no discrimination|
|Mayweather: Nasukawa exhibition back on|
|Witsel: Joining Borussia Dortmund my best career decision|
|Ballon d´Or win would not change Modric´s ´best year´|
|Ireland v New Zealand: Opta stats behind the meeting of the world´s top two|
|The Breakdown: A statistical look at Saturday´s rugby internationals|
|Batshuayi dismisses reports of Valencia departure|
|Brazil must make Copa America final – Tite|
|Rockets rout Warriors as Green goes scoreless|
|Seahawks rally past Packers|
|Lakers G Rondo to miss 4-5 weeks|
|Durant is done with questions about Green|
|Smith, Warner set to return to IPL in 2019|
|No rivalry between Mbappe and Griezmann – Deschamps|
|Neymar: Emery will bring success to Arsenal|
|Jedvaj backs Croatia to deliver against England|
|Howell grabs first-round lead at Sea Island|
|Rooney backing Kane to break England record|
|Betts named American League MVP|
|Republic of Ireland must improve, says under-pressure O´Neill|
|Injured Sergio Ramos to leave Spain squad|
|Yelich named National League MVP|
|Low praises ´beautiful goals´ from Sane and Gnabry|
|Belgium boss Martinez pleased with patient Batshuayi|
|Wilson and Sancho pay tribute to England ´legend´ Rooney|
|Rooney gave England squad a lesson in humility - Southgate|
|This Week in U.S. Sports: LeBron passes Chamberlain, Williamson looking like he is next|
|We still have a chance - Luis Enrique not giving up hope after Spain defeat|
|Rockets ´parting ways´ with Anthony|
|Rooney became ´embarrassed´ at Manchester United|
|Federer: ´Easier´ to play when I´m up against it|
|Rooney convinced England are in safe hands with Southgate|
|Black Caps skipper Williamson confident over first Test availability|
|Federer cruises into last four of ATP Finals for 15th time|
|Republic of Ireland 0 Northern Ireland 0: Randolph saves light up bore draw|
|England 3 United States 0: Experimental side impresses on Rooney farewell|
|Croatia 3 Spain 2: Jedvaj keeps World Cup finalists in contention|
|Belgium 2 Iceland 0: Batshuayi rekindles Hazard flame with match-winning brace|