Celtic romped to a 4-0 win over Partick Thistle, but celebrations were soured by fighting between fans and a protest directed at the club’s board.Frustrations among the Hoops faithful have been threatening to explode, with current chairman Peter Lawwell a chief target of fan ire.Celtic fans displayed banners highlighting previous failures in EuropeShutterstock EditorialOne of those were the humiliating defeat to Hungarian champions Ferencvaros in August 2020Shutterstock EditorialFans in the away end were also seen fighting during the second halfShutterstock EditorialThousands of visiting fans held up posters featuring the 66-year-old’s face and images of key directors with red diagonal crosses over them.Several of the banners were then scrunched up and thrown onto the side of the pitch at Firhill, causing a brief delay to kick-off.Supporters could also be heard chanting ‘all Celtic fans against the board’ and ‘sack the board’ as the players came out of the tunnel.A section of the fanbase didn’t even enter Rugby Park until the 12th minute as part of a protest against the club’s board.Celtic made light work of their Scottish League Cup opponents, scoring two goals on either side of the break to down Partick Thistle.However, tensions still bubbled up in the away end, with some Hoops fans seen fighting among each other during the second half.Anti-Celtic FC board protest banners were seen in and around the scraps, but it is unclear if the two events are in any way related.Why are Celtic fans protesting?A significant section of the club’s fanbase have regularly expressed their dissatisfaction with the board this season.A poor transfer window preceded their humiliating failure to qualify for the Champions League at the end of last month.Celtic were somehow knocked out of the Champions League by KairatGettyCeltic lost to Kairat Almaty from Kazakhstan in a two-legged play-off, before going on to sign Michel-Ange Balikwisha, Marcelo Saracchi and Sebastian Tounekti before the deadline, with former Leicester striker Kelechi Iheanacho later arriving as a free agent.Fans asked why the quartet who were signed did not arrive before the play-off tie, with manager Brendan Rodgers also questioning the timing of the signings.He said: “We all know what it is we need to access, look at and be better at.“You look at Sebastian Tounekti today. If we had him in when we wanted to have him in then it can be a different sport for us.”Rodgers even publicly insisted he would not stay at Celtic Park beyond the expiration of his current deal this summer unless he was promised that failings in the transfer market would be corrected.The latest twist came during his press conference on Friday, when the 52-year-old hit back at a recent media report that cited an unnamed club insider claiming he was trying to engineer an exit.Rodgers’ side sits top of the table on goal difference following the opening five matchesGetty“My honest take is I thought it was a cowardly action by whoever it is,” he said.“It’s not something you’d want. Certainly my relationships with the guys, I am close with here within the board, I would struggle to understand why.“All I’ve tried to do is drive the club forward. Was I surprised by it? Not really.”When asked if the person who was speaking against him should resign, he added: “I don’t think there’s any doubt.”“If you are sitting where I am with the weight I have on my shoulders, it’s so important to feel supported.“Whoever is briefing, they can come here and speak to me at any time.“We all will have frustrations at times in our life, but I would never think of going and bringing that to the fore to hurt someone else.“Especially someone who didn’t have to come back but wanted to come back.”Celtic fans were unhappy with the club’s transfer business this summerGettyHow have the Celtic board responded?Club chief executive Michael Nicholson took collective responsibility on behalf of the board for their Champions League failure on Friday.Nicholson wrote: “Our objective each year is to compete in the Champions League. Unfortunately this season, we suffered a loss on penalties in the tie against Kairat Almaty, which resulted in Europa League entry instead.“As a Board, we take responsibility for the failure to achieve that key objective and commit to improving going forward.“We now look ahead to our Europa League fixtures against FK Crvena Zvezda, SC Braga, SK Sturm Graz, FC Midtjylland, Feyenoord, AS Roma, Bologna FC 1909 and FC Utrecht, where we will hope to perform strongly and progress in the competition.”Celtic chairman Lawwell added that the Celtic board “recognise and share the frustration and disappointment of our supporters with respect to the timing of some of the incoming acquisitions”.He remarked: “The board shares the ambition of our supporters to see the strongest possible team on the pitch and will continue to balance short-term performance with long-term financial stability, and we must factor in the long-term implications of all decisions made today.“This strategy is vital to Celtic and has been pivotal to our success over the last 20 years.”