Chelsea climbed to fourth place in the Premier League as Enzo Fernandez sealed a 1-0 win that piled pressure on beleaguered Tottenham boss Ange Postecoglou on Thursday.
Merino scored in the 20th minute when he stooped to flick his looping header over Robert Sanchez in the Chelsea goal after a Martin Odegaard corner.
Chelsea returned to the top four of the Premier League on Sunday but made heavy weather of their 1-0 victory over struggling Leicester City, squeezing through with a 60th-minute goal from Spain defender Marc Cucurella.
Maresca's side got back on track after three successive defeats with a dominant display at Stamford Bridge.
A lacklustre Chelsea side trailed to Jarrod Bowen's strike three minutes before halftime but improved after the break with substitute Pedro Neto equalising before Aaron Wan-Bissaka's own goal sent the hosts into fourth place.
Manchester City's new signings Omar Marmoush, Vitor Reis and Abdukodir Khusanov will be in the squad for Saturday's league game against Chelsea, boss Pep Guardiola said ahead of the battle between two teams chasing a Champions League spot.
Enzo Maresca's team were just two points behind leaders Liverpool in mid-December, raising hopes of an unlikely title challenge before losing their way.
Ipswich Town put a dent in Chelsea's Premier League title hopes with a 2-0 win at Portman Road on Monday, but the west London side's head coach Enzo Maresca said no one expected his young team to be in their current position this season.
Chelsea's second successive defeat after their Boxing Day loss against Fulham left them without a win in their last three matches.
Chelsea midfielder Enzo Fernandez struggled to live up to his hefty price tag following his arrival at the club in January last year but the Argentine says his recent upturn in form is down to developing a good understanding with coach Enzo Maresca.
Chelsea forward Mykhailo Mudryk has failed a doping test, the Premier League club said on Tuesday, as reports stated the Ukraine international has been provisionally suspended.
The Blues are third in the English top flight, level on 25 points with Arsenal and nine points behind runaway leaders Liverpool.
Enzo Maresca does not believe his Chelsea side are in the Premier League title race despite an impressive start to the season in his first campaign at Stamford Bridge.
Frank Lampard was appointed manager of Championship side Coventry City on Thursday as the former England midfielder aims to rebuild his coaching career.
Chelsea's win, which came after two draws, lifts them to 22 points -- one behind City and three clear of fourth-placed Arsenal ahead of the later kick-offs on Saturday.
Five of the 10 top-flight games in England last weekend saw the result change in stoppage time, including Brentford's 4-3 win over Ipswich and West Ham's 2-1 defeat of Manchester United -- Erik ten Hag's last match as boss of the Red Devils.
Faced with feuding owners, a bloated squad and intense pressure to drag Chelsea out of their malaise, Enzo Maresca has defied expectations by restoring order at chaotic Stamford Bridge.
England winger Madueke hauled Chelsea level but the hosts couldn't find a winner despite their numerical advantage in the closing stages.
Rodri's absence could mean a more prominent role for Matheus Nunes and the Portugal international blasted in his first goal since joining City for £53 million a year ago.
