Eyes on Lampard as City host Blues.

Frank Lampard could make an emotional appearance against former club Chelsea this weekend as his new employers Manchester City host Jose Mourinho's side in an early showdown between the Premier League's heavyweights.
Lampard, who became a talismanic figure at Stamford Bridge before leaving in the close-season after 10 successful years, is in contention for a place in City's midfield for Sunday's game (1500GMT) despite earlier reports that he had asked not to play.
Chelsea have a 100 percent record so far this season, with four wins from four, and lead the table with 12 points, five ahead of fifth-placed City.
Both suffered disappointing nights in the Champions League on Wednesday, however, Chelsea drawing at home to Schalke 04 and City losing 1-0 at Bayern Munich.
In between them are three unfancied teams who will be aiming to maintain their surprisingly strong starts to the season.
Aston Villa, regular under-achievers in recent years, are second but face a major test with a visit by Arsenal on Saturday (1400) while Swansea City and Southampton, fourth and fifth respectively, meet at the Liberty Stadium, also on Saturday (1400).
Louis van Gaal's Manchester United, who kick-started their campaign with a 4-0 win over QPR inspired by new signings Angel Di Maria, Ander Herrera and Daley Blind, travel to Leicester City on Sunday (1230).
Lampard, 36, might have presumed he would never have to face his former Chelsea teammates when he signed for New York City in the summer.
But with the new franchise not entering MLS until next year, the midfielder was given the chance to make a quick return to English football with a loan deal to City.
The ex-England international made his competitive debut for the champions last weekend but he was withdrawn by Chilean boss Manuel Pellegrini at halftime after an unimpressive display.
EARLY BLOW
Yaya Toure's possible return to the City midfield means Lampard might have to settle for a bit-part role as Pellegrini and Mourinho seek to register an early blow in the title race they are expected to dominate.
Diego Costa, the Spain striker with seven goals in four games so far for his new club, will likely be instrumental again in Chelsea's chances of success.
At Villa Park, a Villa team galvanised by Roy Keane's appointment as Paul Lambert's No 2 - and full of confidence after a 1-0 win at Liverpool last weekend - face an Arsenal side outplayed by Borussia Dortmund in the Champions League in midweek.
Danny Welbeck is still looking for his first goal for the Gunners since his 16 million pounds ($26.10 million) move from Manchester United, and manager Arsene Wenger has to contend with more injury problems after Jack Wilshere turned his ankle against Dortmund.
Saturday's game at St James' Park between Newcastle United and Hull City (1400) could be pivotal for both teams.
Newcastle manager Alan Pardew is fighting for his job, according to reports, with his team bottom of the table with two points from a possible 12.
Owner Mike Ashley has given Pardew his support for now, but if 10th-placed Hull inflict another defeat on the Magpies, it could signal the end of the manager's reign - especially as Hull boss Steve Bruce has been tipped by some in the British media as Pardew's potential successor.
In other games this weekend, Liverpool travel to West Ham United on Saturday (1630), Tottenham host West Bromwich Albion on Sunday (1230), and Everton and Crystal Palace meet at Goodison Park on Sunday (1500).