Arsenal are coming off one of their worst campaigns in recent years and are in dire need of change, both on and off the pitch. The Gunners failed to qualify for Europe for the first time in more than two decades and were knocked out in the Europa League semi-finals by eventual winners Villarreal.The Gunners endured a forgettable campaign, mostly because of poor and inconsistent performances from several key players. However, there were a few bright sparks during the season for Arsenal.On that note, let's take a look at the five most valuable Arsenal players at the moment.#5 Kieran Tierney (€32 million)Kieran TierneyScottish left-back Kieran Tierney has been one of Arsenal's standout players this season. He has proven himself to be immensely consistent, reliable and versatile since joining the Gunners from Celtic in 2019 on a €29 million transfer.Tierney's impact at the club in his first season was minimal due to injuries. But the 23-year-old is currently one of the first names in the Arsenal team sheet.This is what we like to hear!https://t.co/zYE3skI2nR— Arsenal FC News (@ArsenalFC_fl) May 27, 2021As per Transfermarkt, Kieran Tierney's market value has increased this season. Arsenal are, however, unlikely to entertain the thought of selling one of their best defenders this summer.#4 Pierre-Emerick Aubameyang (€35 million)Pierre-Emerick AubameyangPierre-Emerick Aubameyang has been one of Arsenal's best signings in recent years. The Gabon striker has scored 64 goals in 114 Premier League games for Arsenal since joining the club from Dortmund in January 2018.However, Aubameyang endured a rather poor season in 2020-21, going by his staggering standards. The striker managed just ten goals in 29 Premier League games. His age and poor performances have led to a massive dip in his market value this summer.18 - Pierre-Emerick Aubameyang has been directly involved in 18 goals in his 17 Premier League appearances against newly-promoted clubs (14 goals, 4 assists), scoring in each of his last five such games at the Emirates. Exploitative. pic.twitter.com/QayVXru0Vm— OptaJoe (@OptaJoe) February 14, 2021Arsenal signed Aubameyang for a club-record fee of £56 million two and a half years ago. The former Borussia Dortmund star is currently valued at only €35 million.