8 big stories to look out for in football this weekend

The unlikely top clash in TurkeyIt's been a wild season in the Turkish Super Lig so far. Incredibly, Fenerbahce are in the relegation zone, defending champions Galatasaray are extremely inconsistent, Besiktas are in deep crisis... and Ryan Babel has left for Fulham.That means none of Istanbul’s big three were in the top four positions at the winter break. As the league restarts this weekend, second-placed Trabzonspor host Istanbul Basaksehir.If the roller-coaster continues, even Malatyaspor and Kasimpasa could become serious title contenders.Serie A’s weirdest head-to-headSassuolo have played Inter Milan 11 times since being promoted to Serie A for the first time in 2013, scored just 13 goals and conceded 20.If they sound like some logical numbers, wait until you hear the other side of it – Sassuolo have won seven matches against Nerazzurri, and lost just four times. That, after Inter enjoyed not one but two 7-0 wins over Sassuolo in the first three fixtures between the two sides. Thereafter it's been revenge all the way for their modest rivals, who have become Inter's nemesis.Sassuolo have won four games in a row against Inter and prevailed in seven out of their last eight meetings. They have triumphed on their last three visits to San Siro. Plainly, Luciano Spalletti, Mauro Icardi Co. are afraid of them.Inter even signed one of Sassuolo's top prospects, Matteo Politano, in the summer – but that didn't help on the opening matchday of the season. On Saturday, the Black and Greens arrive in Milan yet again. Could Inter thrash them 7-0... for a change?Sevilla to punish Solari too?Santiago Solari has to thank Sevilla for him getting the Real Madrid job in the first place. Julen Lopetegui's campaign started rather positively this season, with 13 points from the first five La Liga fixtures, but then came their visit to Andalusia. Sevilla thrashed Los Blancos 3-0, and everything completely fell apart for the former Spain coach from then. A month later, Lopetegui was gone, and Solari got his opportunity.But the Argentine has failed to convince so far, to put it mildly. Madrid have significant problems in attack, are very vulnerable in defence, their problems with benched star Isco usually overshadow everything else, and the coach is still looking for his best formation – to the extent that he tried a radical line-up with three centre-backs at Betis last week. The team played poorly and deserved to lose, but somehow won 2-1.Sevilla arrive in the capital on Saturday, locked level on points with their illustrious rivals. They haven't taken a point at the Bernabeu since 2008, but Pablo Machin’s men look particularly dangerous this time. Would Solari suffer the same fate as Lopetegui?Ceremonial moment for Cech?It’s almost like Petr Cech timed his retirement announcement right before Arsenal vs Chelsea; his current club vs the one with whom he spent 11 years and won 13 major trophies.Cech is an eternal legend at Stamford Bridge, and a lot of Blues fans still feel sorry that he left in rather sad circumstances in 2015. Losing out to Thibaut Courtois was painful for the Czech hero who has also become a bench player at Arsenal. Bernd Leno replaced him in September due to injury, and hasn’t relinquished his spot in Unai Emery’s starting XI.“His commitment hasn't changed with his new situation," Emery has admitted. And so the big question ahead of the weekend must be whether the Gunners should give Cech the honour to play against his former team for one last time.Leno has neither wowed nor disappointed particularly, but the Gunners have only kept one Premier League clean sheet in his 15 matches – and that was in a home fixture against the non-existent attack of rock-bottom Huddersfield. The German hasn't proved himself as a David de Gea-esque saviour just yet.Will Bosz ruin Leverkusen?As the Bundesliga returns from a short winter break, one of its most interesting issues is Bayer Leverkusen's controversial decision to sack Heiko Herrlich and hire Peter Bosz in his place.Results might not have been consistent under Herrlich this season, but the players were behind him, there was a clear system and the team ended 2018 with three wins in four matches.Choosing Bosz is risky – the Dutchman is known for his adventurous style of football, but his ability to organise a defence is questionable. Borussia Dortmund paid millions to land him from Ajax in the summer of 2017, only to later admit their mistake and reluctantly fire him by December. Bayer fans are not excited, and the first test – against the brilliant attack of local rivals Borussia Möchengladbach on Saturday – will be crucial.PSG fearful of the bottom?On paper, there is no contest between the giants of PSG and a rock-bottom Guingamp side on Saturday. In reality, the fixture is spicy because Thomas Tuchel’s side lost at home to the same opposition in the League Cup last week – their first cup defeat in five years.Guingamp won three penalties in the second half, and converted two of them to win 2-1. They also nearly won on their previous outing to the Parc des Princes in April, and led 2-0 before Edinson Cavani scored a late brace to salvage a point for the champions.Add a tight game in August, decided by yet another late brace by Kylian Mbappe, and you get the feeling that Guingamp actually quite enjoy playing against the dominant force in France.Come home, ArjenWhen Arjen Robben announced in December that he will leave Bayern Munich when his contract expires in the summer, his first club smelled an opportunity. Wouldn't it be romantic if the legendary winger returned to Groningen where it all began?Robben joined the academy aged 12 in 1996, made his Eredivisie debut in 2000, and scored 12 goals for the Green-White Army before moving on to PSV, Chelsea and Real Madrid. Groningen fans are trying to convince him, and huge "Arjen, follow your heart" banners were seen at their matches before the winter break.We should see even more of them when Groningen host Heracles on Saturday, despite reports that the club’s management are fairly pessimistic about their chances of landing the legend.O'Neill back at City GroundSpeaking of legends returning home, Martin O'Neill is back at Nottingham Forest. The club is unrecognisable from the days of Brian Clough, but the man who helped them win the European Cup against all odds in 1979 and 1980 is delighted to close the circle at the age of 66.O'Neill could – and probably should – have had a more illustrious career, but if he’s able to lead Forest to promotion just like he did as a player, he will be a happy man indeed. His home debut, on Saturday against Bristol City, should be a cracker.QUIZ!Can you name the 50 most expensive striker transfers of all time?New features you’d love on FourFourTwo.com