Martinez made his Chelsea debut having completed just one full training session. Just five hours after having his much-anticipated signing confirmed by Chelsea, Emiliano Martinez was walking out at Stamford Bridge to play for his new team against Brighton.

Having been thrown straight into the starting XI by manager Xabi Alonso, however, it quickly became clear that he alone cannot solve their defensive problems. The 33-year-old said he was "fit and ready" to play despite his £7.5m signing from Aston Villa being announced so close to kick-off.

In reality, the Argentina international had already trained with his new team-mates after completing his move before Friday's registration deadline, with public confirmation delayed for marketing reasons. There was little blame attached to the goalkeeper for any of the three goals conceded in their 4-3 victory, unlike on Monday, when Robert Sanchez was clearly at fault for the first goal, and arguably the second, in Chelsea's 3-2 win at Fulham.

Either way, that is now five goals conceded in two games. Their impressive new-look attack is the reason, despite the leaky defence, they have a 100% record nonetheless. "A win is a win," Martinez told Sky Sports after his debut. "I know it wasn't a perfect game. But in the end, winning and moving on is what we need. "I am here for a reason. The front three is amazing. When we go forward, we can hurt teams. We had a lot of chances to finish the game. Cole Palmer and Joao Pedro had chances to kill the game. At the back, we need to bring the goals down."

Ex-Premier League goalkeeper Shay Given, who is a pundit on Sunday's Match of the Day, described Martinez as a "brilliant signing". "Martinez is interesting," Given told BBC Sport. "He's only just signed but Alonso's thought 'I'm not messing about, I'm getting him straight in the team'. The manager clearly thinks he needs someone of that sort of stature."

It was, ultimately, victory in chaos, but Alonso will need to find a way to control matches if Chelsea are to become title challengers, with a trip to Arsenal next.

Chelsea beat Brighton in seven-goal thriller to maintain perfect start.

Joao Pedro a central figure - player ratings for Chelsea v Brighton. Martinez is eighth Chelsea-Villa deal in four years. Martinez is a two-time Fifa Best Goalkeeper winner and can point to those individual honours having helped Argentina win the World Cup in 2022 and, more recently, Aston Villa lift the Europa League in May.

"I am happy with his first impact," said Alonso after the win over Brighton. "He has been in the building for 48 hours so now we will have the whole week to prepare for the next one and day by day we will feel his presence because he has this charisma, this aura to influence and to have a very positive connection with the rest of the team."

By contrast, Sanchez had not won any major silverware before joining Chelsea from Brighton for £25m in 2023. Both statistically and through the eye test, Sanchez compares favourably with many goalkeepers, which is why Chelsea head of goalkeeping Ben Roberts retained faith in him for so long.

However, Sanchez has proved prone to errors, particularly during the 2024-25 season, and temporarily lost his place to Djordje Petrovic, now at Bournemouth, and Filip Jorgensen, now at Strasbourg, before regaining the starting role. Despite making only one error leading to a goal last season, compared with three by Martinez at Villa, Sanchez is now considered available for transfer and has fallen to fourth in the goalkeeping pecking order at Stamford Bridge.

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Alonso praise for Joao Pedro 'desire'. Asked what will happen to Sanchez, Alonso said: "We will see. Sometimes you have to take tough decisions." It is a ruthless outcome for the Spain international, who was backed publicly by Alonso and privately by senior figures at the club before they changed course.

A closer look at last season's statistics suggests that Martinez produced stronger underlying numbers than Sanchez despite making more errors leading to goals. Martinez conceded fewer goals, recorded a higher save percentage, prevented more goals relative to the quality of shots faced and posted significantly better passing accuracy. The Argentine has already won over a lot of supporters, asking John Terry for permission to wear the number 26 shirt at Chelsea.

"I spoke with Chelsea legends John Terry and Petr Cech," he said. "I know how big this club is and what we want to achieve this season. I came here to help. I have come here to challenge and to try and win the Premier League. I trained only one day with the team. The guys have treated me really well in the last day or two. I know the talent we have up front. I try to bring that solidity in the back."

Alonso will be concerned by his side's struggles to keep possession and their vulnerability from set-pieces. Remarkably, Chelsea recorded 25.9% possession against Brighton, the lowest in a league match managed by Alonso across his spells at Chelsea, Bayer Leverkusen and Real Madrid. They also completed just 146 passes, Chelsea's lowest figures on record (beginning in 2003-04) in a Premier League match.

That inability to keep the ball comes as Enzo Fernandez's exile from the first team entered a second match, with Manchester City expected to make a bid before Tuesday's transfer deadline. The Blues also had concerns over Moises Caicedo's fitness, and he was forced off just 11 minutes into his substitute appearance. Malo Gusto and Romeo Lavia started in central midfield, while Jordan Henderson was also unavailable through injury and Valentin Barco was seemingly not yet trusted to start a Premier League match.

It is no surprise Chelsea are exploring a move for Lamine Camara and want to ensure a replacement is lined up should Fernandez join City in a deal expected to be worth more than £120m. A lack of midfield protection, coupled with a switch to a back three after largely operating with a back four last season, left centre-backs Wesley Fofana, Maxence Lacroix and Levi Colwill looking vulnerable at times.

Chelsea have scored a remarkable seven goals in their opening two league matches but have also conceded five. They have now gone 18 games without a clean sheet, their longest such run since the 1960s. In typical fashion, Alonso played down any concerns that his side almost threw away a three-goal lead. "No, I would say it is quite normal," he said. "It happens in many teams, other teams that they have already worked for and they are together and they have more games together."

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