Two of world football's great tacticians go head-to-head for only the second time in a competitive match when Jose Mourinho's Chelsea puts its unbeaten record in the Premier League on the line against Louis van Gaal's Manchester United on Sunday.
Mourinho was given his break in management by Van Gaal when he worked as an assistant to the Dutchman at Spanish side Barcelona from 1997-2000, and the mutual respect between the pair lasts to this day.
When Mourinho's Inter Milan beat Van Gaal's Bayern Munich 2-0 in the 2010 Champions League final, it was a win for the pupil over his master.
Four years on, they are now regarded as two coaching veterans managing two of the game's other great clubs. It gives the match at Old Trafford a fascinating sub-plot.
"Maybe it will be a tactical affair," United midfielder Daley Blind said. "I think both coaches are very strong at that point, so maybe it will be a tight game."
Chelsea heads to Manchester as the Premier League leader and the only unbeaten team after eight games. United is 10 points behind in sixth place.
Here are some other talking points ahead of this weekend's matches in England's top league:
Chelsea could be without Diego Costa for a third straight match, with the Spain striker having been admitted to a hospital with a severe stomach virus in the days after his return from international duty.
Costa, who has also been struggling with nagging hamstring problems, has been released from the hospital and his condition is improving, but it's unclear whether he'll be ready to play on Sunday.
He is the tied with Manchester City striker Sergio Aguero as the top scorer in the division with nine goals.
Mourinho could also be missing another striker for the weekend as Loic Remy limped off with a groin injury during the 6-0 win over Maribor in the Champions League on Tuesday.
United captain Wayne Rooney is also out as he serves the final game of a three-match suspension.
WHY ALWAYS HIM?
After his latest brush with controversy, Mario Balotelli may find himself on Liverpool's substitutes' bench for Saturday's home match against Hull.
Liverpool manager Brendan Rodgers reprimanded Balotelli for exchanging shirts with Real Madrid defender Pepe as they walked off the pitch at halftime of a Champions League match on Wednesday.
"Any action will be kept between ourselves," Rodgers said Thursday. "We just had a conversation about the culture in this country and in particular Liverpool and that is it. Matter closed."
Balotelli, still without a league goal since joining from AC Milan in August, was replaced at halftime of the 3-0 loss to Madrid after another ineffective performance. Rickie Lambert could start up front for fifth-place Liverpool at Anfield.
"He is genuinely working hard and doing his best at Liverpool," Rodgers said of Balotelli. "Longer term, we will see how that works out for him. . As long as he is doing his best, that is all I can ask as a coach — whether that best is going to be good enough that remains to be seen."
On the wrong end of an 8-0 hammering last weekend, Sunderland goes looking for payback when it hosts Arsenal on Saturday.
Sunderland's players have offered to refund the travel and ticket costs for the 2,500 fans who made the 700-mile trip to watch the team capitulate at Southampton on Saturday. Any unclaimed money will go to a local hospice.
"It's a decision they made and I totally respect it," Sunderland manager Gus Poyet said Thursday.
Arsenal, which has defensive problems with Mathieu Debuchy and Laurent Koscielny out injured, is without a win in three league games and is already 11 points behind Chelsea.
Second-place Manchester City, which is five points behind Chelsea, heads to fourth-place West Ham with Aguero looking to score for a sixth straight game in all competitions.
Southampton, a point behind City in third, hosts Stoke. Also, it's West Bromwich Albion vs. Crystal Palace and Swansea vs. Leicester on Saturday.
On Sunday, it's: Burnley vs. Everton; and Tottenham vs. Newcastle. Queens Park Rangers hosts Aston Villa on Monday.