Arsenal boss Mikel Arteta said he would bet on Kai Havertz returning before the end of the season as his recovery from a hamstring injury is ahead of schedule.
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 have signed defender Tosin Adarabioyo from Premier League rivals Fulham on a free transfer.
Former Chelsea and Tottenham coach Antonio Conte was hired by Napoli on Wednesday as the deposed Serie A champions try to bounce back from their disastrous league title defence.
The Italian will leave Leicester City, whom he led to promotion back to the Premier League in his first season in charge, and begin his new role on July 1, Chelsea said in a statement.
Chelsea have appointed Leicester's Enzo Maresca as their new head coach, according to British media reports late Thursday.
Chelsea's stars praised Mauricio Pochettino on Wednesday following the Argentine's ruthless sacking after just one season in charge.
"Chelsea FC can confirm that the club and Mauricio Pochettino have mutually agreed to part ways," Chelsea said in a statement.
"I don't know about the rumours about the review. My staff tomorrow are flying [on holiday]. Maybe tonight if [club bosses] decide another thing or tell us to stay, [otherwise] they'll go for a holiday."
Chelsea manager Mauricio Pochettino has revealed he feared the sack after an embarrassing 4-2 defeat against Wolves earlier this season.
Olivier Giroud confirmed on Monday that he will leave AC Milan at the end of the season to end his long career in Major League Soccer.
Mykhailo Mudryk also scored for Mauricio Pochettino's Chelsea, who are seventh in the table with two games remaining, fuellng their hopes in the race for a European spot next season
