Vital clash at the summit

While this weekend may only be the 19th of the Bundesliga's 34 rounds, the destination of the league title may well be determined by Sunday's winner of Bayern Munich's clash with Werder Bremen.
Bayern's club manager Uli Hoeness acknowledges the "utterly crucial fixture" at Munich's Allianz Arena and a win could put leaders Bayern six points clear of Bremen in second and nine points clear of third-placed Bayer Leverkusen.
"We've always said we're in a good position for the second half of the season, because with the exception of Schalke, we play all our main rivals at home," said Hoeness.
"But it's still an utterly crucial fixture for us, because a win would see us pull a little further clear of Bremen.
"I don't think any of us believed we'd be three points ahead of Werder going into the game."
There is nothing more Munich coach Ottmar Hitzfeld would enjoy than to have a six-point lead come Sunday night and the last time the sides met in the league cup last August, Bayern enjoyed a 4-1 victory.
But the home side will be without French midfield star Franck Ribery, who has a hamstring injury, and Germany international Bastian Schweinsteiger will be under pressure to lead Bayern's attack.
Bayern will be miss the hard edge Ribery gives Bayern's midfield and having already blown a six-point lead between October and Christmas, confidence is an issue for the Bundesliga giants chasing their 21st German title.
Bremen will be desperate for a win to avoid their third-straight defeat after their German Cup lose at Borussia Dortmund and last weekend's humbling defeat by VfL Bochum.
There will be a huge battle at Bayer Leverkusen after they stole third place from Saturday's visitors Hamburg last weekend.
After being hammered 4-1 at Schalke 04 last weekend, VfB Stuttgart will be looking to bounce back against Hertha Berlin, who themselves were humbled 3-0 at home to Eintracht Frankfurt and have gone five games without a win.
The Royal Blues of Schalke have put themselves into fifth place with their drubbing of Stuttgart, but will have a tough time at neighbours and fierce rivals Dortmund on Sunday.
Having led the Bundesliga going into last season's dying stages, Schalke were beaten 2-0 0 in Dortmund last season, which cost them the title and coach Mirko Slomka will want no repetition.
After bagging a hat-trick on his Frankfurt debut last weekend, Czech striker Martin Fenin will be looking to add to his tally when his eighth-placed side play strugglers Arminia Bielefeld on Friday.
Nuremberg have the chance to drag themselves out of the bottom three when they take on Hansa Rostock who hover just one place about them in the table.
Bottom side Duisburg will travel to mid-table Wolfsburg with three points not enough to take them out of the bottom three, while Karlsruhe and Hanover will aim to improve their chances of breaking into the top five when they meet.