Former Arsenal midfielder Emmanuel Petit believes that sacking Arsene Wenger would be "the biggest mistake" Arsenal could make, amid speculation that the French manager could be on his way at the end of the season. Rumours that Wenger's 16-year reign at the north London club could soon be over are swirling, as Arsenal look destined to finish the season without a trophy for the seventh straight campaign after their FA Cup defeat at Sunderland Saturday. That topped a woeful week which also saw AC Milan inflict a heavy 4-0 defeat on Arsenal in the first leg of their Champions League last-16 tie. But Petit, who formed a formidable partnership with Patrick Vieira in the early stages of Wenger's tenure, is convinced his former boss remains the right man to get the misfiring English giants back on track. "If Arsene has to leave the club they need to find a big manager to settle down and that would be very difficult for the next manager," he told the BBC in an interview published on Monday."I think Arsene's still the solution. They need to change a few things in the transfer market, change a few things in their politics to bring a competitive team." Petit, who joined Arsenal in 1997 and helped the team win the Premier League and FA Cup double in his first season, pinpointed last season's League Cup final defeat to Birmingham as a turning point. Now the club needs a change of tack in the transfer market to get more leaders on board, as psychologically the team was "very weak", Petit said. Petit said Wenger had to be applauded for changing the team after his side and for putting his faith in young players, which made financial sense. But he added: "They need more experienced players, more big characters in the team because the quality is there and they need some players to be the mentors in the team."