Just a decade ago, when Barcelona were flying high and were the champions of Europe, it looked like they could hardly put a foot wrong. The team was brimming with talent and there seemed to be no stopping them.However, at the start of this new decade the Cules look anything but comfortable. Barcelona are still in the UEFA Champions League fight but it's been a rather forgettable season for them. The sheer number of issues that have cropped up around the team this season is alarming.Barcelona will need to change a lot things if they are to get back to the top, where they belong. Let's analyze 5 of the biggest mistakes that Barcelona committed this season.#5 Sacking Ernesto ValverdeErnesto ValverdeWhile the fans were certainly divided on Ernesto Valverde and his pragmatic approach towards football, in hindsight, sacking him halfway through the season when Barcelona were leading the league seems like a horrendous decision especially if you look at what transpired after that.Valverde was sacked on the back of Barcelona's loss to Atletico Madrid in the semi-finals of the Spanish Super Cup. It was for the first time in 17 years that Barcelona had sacked a manager halfway through the season and it didn't work out in their favour.Quique Setien, a proponent of possession-based football, failed to deliver the goods and Barcelona hardly ever played the attack-minded game that the 61-year-old was expected to bring. Valverde's Barcelona side might not have been very easy on the eye but they still used to get their job done.2011 - Ernesto Valverde is the first manager to be sacked when leading in one of the Top 5 European leagues since Antoine Kombouaré with Paris in December 2011. Peculiar. pic.twitter.com/Q1G81H4Z8t— Optajean (@OptaJean) January 14, 2020#4 No cohesion between Barcelona board and playersEric AbidalThis is a cause of growing concern to fans as the Barcelona board and the players seem to be operating at different wavelengths. It turned quite ugly this season as Eric Abidal, the Barcelona sporting director, and Lionel Messi locked horns in a public spat.It started after Eric Abidal, in defending his decision to sack Ernesto Valverde in an interview, claimed that the Barcelona players weren't satisfied nor worked hard under the former manager. The players perceived the comment to be in bad taste as work ethic is not something that's taken lightly about when it comes to professional footballers.Lionel Messi immediately took to Instagram and asked Abidal to name the players and asked for the club's management to take responsibility for its decisions. Josep Maria Bartomeu stepped in and calmed the waters but it remains an ugly chapter in a forgettable season.The club has become dysfunctional and the lack of cohesion between the management and the players is disheartening to see.Leo Messi on criticism from Barca's sporting director Eric Abidal and on a potential Neymar return 🗣 pic.twitter.com/HnBjADSVJb— B/R Football (@brfootball) February 20, 2020