Arsenal manager Mikel Arteta arrived like a whiff of fresh air in north London, instantly transforming the fortunes of a largely mediocre team. Although the club couldn't finish in the top 4 and return to the UEFA Champions League, Arteta's men lifted the FA Cup by flooring Manchester City and Chelsea in successive games. The club began its 2020-21 season on a promising note by beating reigning Premier League champions Liverpool in the Community Shield. With a 3-0 win over Fulham on the opening day of the season, Arsenal topped the Premier League table and followed up with a 2-1 home win over West Ham.However, since then, Arsenal have been in freefall, losing seven of their next ten league games, to languish in 15th place in the league table. The Gunners are currently on a debilitating four-game losing streak at home following their 0-1 reverse against Burnley, their worst streak in the English top flight in more than six decades.4 - Arsenal have lost each of their last four Premier League home games, their worst top-flight run on home soil since December 1959, a sequence which also included defeat to Burnley. Lonely. #ARSBUR pic.twitter.com/kOmUXBeY9Z— OptaJoe (@OptaJoe) December 13, 2020Five reasons why Arsenal are struggling under Mikel Arteta in 2020-21Despite a promising start to his managerial reign, Mikel Arteta's Arsenal have had a spectacular meltdown, especially in the league, this season.With the pressure mounting on Arteta with every passing 'non-result', let us have a look at a few reasons why Arsenal are struggling under the Spanish tactician this season.#1 Pierre-Emerick Aubameyang's reduced efficacy in an unfamiliar positionPierre-Emerick AubameyangAfter arriving at Arsenal in 2018, Pierre-Emerick Aubameyang amassed an impressive 70 goals in 109 games in all competitions before this season.The former Borussia Dortmund man, who was the Torjägerkanone winner in 2016-17, repeated the trick in the 2018-19 Premier League. Aubameyang celebrated another 22-goal league season last campaign but has uncharacteristically hit a lean phase.Pierre-Emerick Aubameyang has scored two goals in 10 appearances since signing his new three-year Arsenal contract 🤔 pic.twitter.com/eBszV62XWN— Goal (@goal) November 30, 2020A return of just two goals in 12 Premier League games this season from their star striker has had a direct effect on goal-shy Arsenal's performances. That has got exacerbated, as Arteta has played Aubameyang away from his favoured centre-forward position, which has meant that the Gabon international's shots per game saw a sharp drop.Aubameyang has often looked lonely on the wings and needs to get back to his favoured position and see more of the ball. If that happens, the striker would have more shots on goal, and Arsenal would be the better off for it.#2 Lack of goalsArsenal have struggled to score goals this season.With their star striker Aubameyang not producing the goods up front, Arsenal have scored a meagre ten goals in 12 Premier League games this season.It is the Gunners' worst scoring record in the league in nearly four decades since managing only eight at this stage of the 1981-82 league season.10 - Arsenal’s tally of 10 goals after 12 Premier League games is their lowest at this stage of a top-flight season since 1981-82 (8 goals). Nonsensical. #ARSBUR pic.twitter.com/5C8FOYwr81— OptaJoe (@OptaJoe) December 13, 2020With the likes of Alexandre Lacazette and Willian failing to up the ante amidst Aubameyang's poor form up front, Arsenal have struggled to score goals.Willian has been especially poor since his arrival at Arsenal in the summer. The experienced campaigner is yet to score a league goal for the club and hasn't assisted one since the opening day of the season.Arteta needs to find a way to unleash the creative prowess of Willian, else the Brazilian would have to be relegated to the bench.