The injury to the Chile forward, who was left out of the squad for Tuesday's Champions League victory over Young Boys, "will require further investigation to confirm its severity", the club added.
Chelsea will give a better account of themselves in the Champions League in Paris on Wednesday than they did in an unexpected weekend defeat at CrystalPalace, manager Jose Mourinho said on Sunday.
Aston Villa beat Crystal Palace 1-0 to win a Premier League match for the first time since August while a late goal from Paul Dummett earned a 3-3 draw for Newcastle United against Manchester United on Tuesday.
Rediff.com brings you the second instalment of the Best Sports Photos of the Year!
Stoke City manager Mark Hughes says he will not contest the Football Association's misconduct charge against him after he was sent off in Saturday's 4-0 Premier League defeat by Tottenham Hotspur.
Champions Liverpool suffered a shock 1-0 defeat to lowly Burnley on Thursday, ending their 68 match unbeaten home record in the Premier League as their title defence continued to fade.
'The accumulation of the games, I never had that'
Leicester City manager Claudio Ranieri will deliver on his vow to buy pizza for the squad after they kept their first clean sheet of the season in beating Crystal Palace 1-0 at the weekend.
Sunderland striker Steven Fletcher scored in each half to help his beleaguered side earn a much-needed 3-1 win at Crystal Palace in their Premier League match at Selhurst Park on Monday.
Premier League clubs West Bromwich Albion and Watford were knocked out in the League Cup second round by lower-league opponents on Tuesday as a strong Liverpool side crushed championship Burton Albion 5-0.
Players from both teams took a knee in solidarity with the Black Lives Matter movement before Wednesday's game at Toyota Stadium in Frisco, Texas, but their gesture was overshadowed by booing from a small section of fans.
News of all that transpired on and off the football field.
Manchester United eased the pressure on manager Ole Gunnar Solskjaer with a 3-1 win at Everton in the Premier League on Saturday with Bruno Fernandes scoring twice and Edinson Cavani grabbing his first for the club.
Hull City and Swansea City earned valuable victories in their battle for Premier League survival but Middlesbrough slid further towards the drop after a 4-0 hammering at Bournemouth.
Manchester United will travel to third-tier MK Dons in the Capital One Cup second round following the draw on Wednesday, the first time they have been involved at this stage of the competition for 19 years.
Images from the English Premier League matches played on Sunday.
Images from the English Premier League matches played on Saturday
Real Madrid's Portugal striker Cristiano Ronaldo was crowned the best soccer player in the world for the second year running at FIFA's The Best awards gala on Monday.
Alex Ferguson could return to a job in football management despite his retirement at the end of last season, according to his old Arsenal adversary Arsene Wenger.
Chelsea landed a potentially decisive blow in the Premier League title race with a 2-1 win at Aston Villa on Saturday that put them seven points clear of Manchester City, who self-destructed in a 1-1 draw at home to Hull.
Sergio Aguero scored five times in 20 minutes including an eight-minute hat-trick as Manchester City came from behind to thrash Newcastle United 6-1 and go back to the top of the Premier League table on Saturday.
Chelsea ran riot at Swansea City, scoring four times before halftime on the way to a 5-0 win that sent Jose Mourinho's side five points clear in the Premier League on Saturday.
Southampton's bustling midfielder Victor Wanyama will be out for "a few weeks" after injuring his hamstring moments before he was due to be substituted in their FA Cup third-round replay win at Ipswich Town on Wednesday.
IMAGES from the EPL match played between Arsenal and Newcastle on Monday
Champions Leicester City will begin their Premier League title defence with a trip to newly promoted Hull City on August 13, according to the 2016-17 fixtures released on Wednesday.
Liverpool needed two extra-time goals to beat NottsCounty 4-2 at Anfield on an eventful night for the Premier League clubs in the League Cup second round on Tuesday.
Having spent much of his time at Chelsea operating in Eden Hazard's shadow, Willian has emerged as a leading light in the team ahead of their Champions League showdown with Barcelona.
Champions Manchester United travel to Swansea City for their first Premier League match under new manager David Moyes, while Manuel Pellegrini's Manchester City are at home to Newcastle United on August 17.
IMAGES from Premier League matches played on Saturday.
Images from the English Premier League matches played on Wednesday night.
The destination of the Premier League trophy will not be decided when current champions Chelsea meet their immediate predecessors Manchester City.
Manchester's police commissioner demanded an inquiry into the 'fiasco' of a fake bomb left behind from a training exercise at Old Trafford that forced the abandonment on Sunday of a Premier League soccer match.
The Premier League game between Manchester United and Bournemouth on Sunday was abandoned after two stands at Old Trafford were evacuated before kickoff.
LeicesterCity manager Claudio Ranieri says it will be "amazing" to walk onto the pitch as a league champion on Sunday at Chelsea, the club that sacked him 12 years ago.
Currently, players from outside the EU must gain work permits and pass a series of qualification tests to get a "governing body endorsement" and work permit.
Goalkeeper Alisson Becker scored a stunning header in the fifth minute of stoppage-time as Liverpool snatched a 2-1 victory at the death against relegated West Bromwich Albion at The Hawthorns on Sunday.
IMAGES from soccer matches played in the EPL, La Liga and Serie A on Tuesday.
Fans return to English grounds, but told not to celebrate goals too much.
Guardiola said City had plenty of options, with Gabriel Jesus the only main striker fit and ready but Ilkay Gundogan and Raheem Sterling are able to slot into the role.
Liverpool's hopes of winning their first title in 24 years suffered a huge setback when they lost 2-0 at home to Chelsea and Manchester City took advantage with a 2-0 victory at Crystal Palace.