Raheem Sterling was restored to Chelsea's attack and rewarded Graham Potter with a starring role in a 2-1 win over Dinamo Zagreb which saw Ben Chilwell limp off late on
Chilwell appeared to pull his hamstring chasing a ball in stoppage time and though he got to his feet and played the final seconds of the match, the England defender had to be carried across to the tunnel at the full-time whistle to raise questions over his fitness ahead of the World Cup, which kicks off in less than three weeks
"You'd have to say [the World Cup is a concern] yes," said Chelsea boss Graham Potter when asked about his prognosis
 "I don't want to add any more than that, but when a player pulls up like he did and felt it, it's never positive
"Sterling's role in Chelsea's 4-1 defeat at Brighton on Saturday was called into question after Potter started him at wing-back, but back in his natural position he scored his first goal for the club since mid-September to cancel out Bruno Petkovic's early opener - and he could have had a first half hat-trick but missed two other chances
With Chelsea only playing for pride, but needing to shake off the memory of that hammering on the south coast, they could not have got off to a worse start when Cesar Azpilicueta's miscued header teed up Petkovic to stoop and nod home after seven minutes
Dinamo were playing for their European hopes - needing a win and favourable results elsewhere to qualify for the Europa League play-off round - but were pegged back only 11 minutes later, when Sterling latched onto Pierre-Emerick Aubameyang's backheel and bent an equaliser inside the far post
On the half-hour mark, Chelsea put themselves ahead as a low ball from the right found debutant Denis Zakaria, who marked his first appearance since joining the club two months ago with what would prove to be the winner, a smart near-post strike which crept inside the near post
Aubameyang hit the bar after half-time as Chelsea pushed for a cushion while Josip Sutalo was kept out by Edouard Mendy at full stretch, but a dead rubber for the hosts ended with a reassuring victory to end their group-stage on a high ahead of Monday's last-16 draw
After being forced to change his favoured back three several times in recent games, Potter reverted to a four-man defence for the first time in eight games hoping to provide more balance to the strong side he had picked
Things could not have got off to a worse start
 Chilwell failed to block a cross which Azpilicueta got his head to but could not direct clear, and with Kalidou Koulibaly caught on his heels Petkovic was presented a simple finish to open the scoring
That changed Dinamo's gameplan from having to score to battening down the hatches - not that it worked for long
Sterling could already have scored from a delightful, disguised diagonal into the box from deep from Kai Havertz, but fired over on the volley
He made amends soon after, meeting Aubameyang's backheel and riding two challenges before deftly curling home on his left
The England forward could have had a hat-trick on another day but blazed the most presentable chance of the three well off target
Instead, debutant Zakaria completed the turnaround on the half-hour when connecting sweetly with a low ball which just beat Sadegh Moharrami's attempted goal-line clearance
Sutalo could have levelled up within minutes of the restart but was denied by the recalled Mendy from a corner, before Aubameyang rattled the crossbar from 20 yards as the game began to open up
It could have been three late on as substitute Conor Gallagher was denied from close-range, but appeared to be destined to be a positive night for Chelsea regardless - until Chilwell's injury put a dampener on the evening's events, and perhaps his World Cup hopes too
"Ben's a blow for us on an otherwise positive evening
 To see him pull up like that, it's not a great sight
 So fingers crossed when we get it scanned it isn't too bad
 It can be not as severe but we have to cross our fingers at the moment
 But clearly, we're disappointed
"I spoke to him briefly
 He just felt something as he was setting off
 He is disappointed and upset
"We've tried to play Raheem as high and wide as we can
 I know there is a lot of talk about him being a wing-back, but I played as a wing-back and I can assure you that Raheem has never played as a wing-back! He has never been asked to play and defend in a back five or back four even
"His responsibility has always been against the full-back
 With the back four behind him tonight probably helped, he was a little bit higher and a little bit wider
 It was nice for him to score because he has been working hard for the team
 As I said before, the team has to function well for the individuals to do well
 So I'm really pleased he got his goal today
"Chelsea have three more games before the World Cup break
 They host Arsenal in the Premier League on Sunday; kick-off 12pm
 They then travel to Man City in the Carabao Cup, live on Sky Sports; kick-off 8pm
Chelsea's final Premier League game before the tournament is on Saturday November 12 when they travel to Newcastle, live on Sky Sports; kick-off 5
30pm
Dinamo Zagreb will also play three more games ahead of the World Cup, twice in the league and one Croatian Cup fixture next week
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