Zenit St. Petersburg go into this weekend’s Russian Premier League matches knowing a slip from leaders CSKA Moscow could see them tie for points in top place, and they have extra motivation after spurning that very opportunity last week. Zenit, unbeaten in their last 10 matches and just two points off CSKA’s lead on 40 points, travel to Samara to face bottom team Krylya Sovetov.  It’s a potentially awkward game for Zenit, however, who dropped two points at home to Amkar last weekend and face a Krylya team on a three-game unbeaten streak. Leaders CSKA, in their worst patch of form since the start of the season after two draws and a loss in their last three, host Tomsk, who are on a slide after three straight defeats and facing financial difficulties with the regional government threatening – again - to cut off funding. Anzhi’s match Sunday against Dinamo Moscow is a sellout after Inter Milan striker Samuel Eto’o looked certain to move to Makhachkala, but talks broke down late Thursday with Anzhi and Inter reportedly 6 million euros apart in their valuation of the player. Third-placed Dinamo last week thumped Terek Grozny 6-2 to reel in the top two, who both drew, and will look for a repeat this weekend against Terek’s rival in the Caucasus, Anzhi. Anzhi, nine points off the lead in sixth, were beaten 3-0 at Spartak Moscow last week and will look for a more convincing display against Dinamo and from new acquisition Yuri Zhirkov. Zhirkov has faced incessant boos and whistles from the crowds since he signed from Chelsea earlier this month – a hostile reaction to his decision to join a team from the mainly Muslim region of southern Russia. In other matches, Rubin, fresh from a 3-1 defeat to Lyon in the first leg of their Champions League playoff on Tuesday, travel to Amkar Perm; Terek seek to rebound from the Dinamo trouncing against Rostov; and Spartak Moscow, eight points off the lead in fourth,  play at joint-bottom club Spartak Nalchik. Elsewhere, eighth and ninth face off as Lokomotiv Moscow host Krasnodar, and Kuban host Volga Nizhny Novgorod. The Russian Premier League is in transition as it switches from a summer to a winter season in a move to synchronize with European leagues. The current 2011-2012 season stretches over 18 months and is played in two stages; the first phase, which is currently two-thirds through, is a regular schedule in which each team plays each other team twice. After a winter break, the top eight and the bottom eight separate to form two mini-leagues in which each team plays the other twice. Teams in the top league will fight for the championship and places in European competitions, while teams in the bottom league try to avoid relegation.