It says everything about the crisis at Arsenal these days that a teenager can make his first start in nine months, touch the ball 11 times and come off injured after 49 minutes yet still be their best player by some distance.Gabriel Martinelli was the brief flicker of light on another dismal evening for Mikel Arteta as Manchester City ran out easy 4-1 winners at the Emirates to move into the EFL Cup semifinals. Darkness envelops the Gunners these days, so much so that Martinelli’s enterprise and endeavour stood out like a beacon.- Stream ESPN FC Daily on ESPN+ (U.S. only)- ESPN+ viewers guide: Bundesliga, Serie A, MLS, FA Cup and more”Gabi [Martinelli] has a unique energy and a way to transmit his passion for the game. I think he plays the game in a different way to any other player so it is hard to compare him”, said Arteta afterward. “But it is great to have him back, to bring that spirit, that fight and after such a long time [out] to play against this opponent, the way he did it I think in the first half, it is something to be really proud of.”At one point while palpably limping with the ankle injury which eventually forced his substitution, he still moved quicker than Alexandre Lacazette, whose first-half equaliser should not mask another performance bereft of so many basics including application and energy.Editor’s PicksArsenal, Arteta need to focus on results, not stats; Bayern get lucky; Barca in limbo; Messi ties PeleArsenal, Arteta concern as Auba faces scanArsenal must stick with Arteta and focus on clearing out the squad after defeat at EvertonThis was in fact the problem with many of this starting line-up. Centre-back Shkodran Mustafi does not want to play for Arsenal anymore and is really committed to that stance by failing to mark anyone in his vicinity; Gabriel Jesus opened the scoring inside three minutes finding space to meet Oleksandr Zinchenko’s pinpoint delivery with embarrassing ease.Midfielder Dani Ceballos will be returned to Real Madrid when his loan spell ends and that time looks like it cannot come soon enough. Left-back Sead Kolasinac is also likely to depart having almost left in the summer, Lacazette too if a buyer can be found.”We have to turn it around or we are in big trouble. It is the moment which will decide our season”, said Arteta after the defeat.” I am focused on the fighters and going against a really difficult opponent.”I see a lot of fighters. We are looking at options, players coming in and out. It’s a really complicated window with the pandemic.”Goalkeeper Runar Alex Runarsson is just starting out on his Arsenal career but he is woefully short of the required level, a third-stringer at best, and after shaky displays in the Europa League, City exposed his shortcomings again here, most notably when Riyad Mahrez’s 54th-minute go-ahead free-kick squirmed through his hands.In contrast, Martinelli was injured chasing down a lost cause and colliding with City goalkeeper Zack Steffen shortly before the first half ended. The Brazilian, back in the team after undergoing knee surgery earlier in the year, epitomised the desire Arsenal must show to grind their way up the Premier League table.Gabriel Martinelli was Arsenal’s lone bright spot in their cup exit to Man City, the 19-year-old making an impressive first start after nine months out injured. Photo by ADRIAN DENNIS/AFP via Getty ImagesHe showed his class, too, and importance given Arteta’s attacking style is so focussed on accurate crossing, producing two excellent deliveries from the left flank — one with each foot just for good measure — the second of which Lacazette buried with the efficiency Arteta has been calling for.Arteta has been keen to keep pressure off young Martinelli’s shoulders but although he only touched the ball 11 times and took on one player according to Opta, it was his sheer willingness to graft that sparked Arsenal into life.And each time the Spaniard bemoans a lack of clinical finishing among his forwards, Martinelli’s record of 10 goals from 15 starts (and 12 substitute appearances) feels more significant. Arteta was so desperate to keep Martinelli involved that he began the second half despite hobbling through the final minutes of the first and walking off with blood seemingly seeping through his right sock.He lasted four minutes, replaced by £72 million signing Nicolas Pepe, who continues to look half the player for 10 times the price. Martinelli cost just £6m from Ituano in July 2019 but that shrewd acquisition is very much an exception to Arsenal’s recent business, and Arsenal count to pay the price for poor recruitment on nights like this.City undeniably picked a stronger team with Pep Guardiola clearly placing some value in attempting to secure this trophy for the third consecutive season, but Arsenal still had three players out there signed for £46.5m, £35m and £23m. This was not an Under-23s line-up but one that relied on a squad depth that is simply without the requisite quality.Arteta was understandably disappointed with how the game unravelled. “We conceded a really soft goal after one or two mins. At the moment we are, it’s difficult against a really good opponent.”We got back into the game and scored a really good goal and had a spell of 25 mins where we were the better team. We conceded a second and against a team like that they really penalise you. After that, we were chasing it.”Harsh truths are needed for Arsenal to emerge from this slump. An extended cup run may have papered over the cracks just as it appeared last season’s FA Cup Final success did — and arguably their three wins in the latter days of Arsene Wenger’s reign did too, given this is a club aspiring to challenge for the Premier League and Champions League.There will be no EFL semifinal early in the New Year and that should be a good thing, giving Arteta time to work with his players on the training ground to iron out flaws that currently seem immovable. Having Martinelli available in the coming weeks would no doubt help considerably. But the rest of Arsenal’s squad needs to make sure that even in this rusty condition, Martinelli doesn’t stand out as the sole hope.