Ronald Koeman hopes Barcelona's defeat to Celta Vigo was not Lionel Messi’s final game at the Nou Camp. Asked after the match if it was indeed the Argentine's last appearance at the Nou Camp, the Barcelona manager replied:“I hope not because I think against Celta he’s shown his effectiveness and that he’s still the best in the world.”Barcelona suffered a humiliating 2-1 defeat to Celta Vigo. The defeat meant that the Catalan giants mathematically would not be able to win the La Liga title going into the final game of the season. Due to Barcelona's shortcomings in the league this season, Lionel Messi's future at the Nou Camp is in doubt.Messi opened the scoring in the game, netting his 30th league goal of the campaign. However, Celta Vigo turned it around, causing Barcelona fans to wonder if it was indeed their club captain's last home game since his contract will be expiring at the end of the current season.Messi’s game vs Celta Vigo was rated 10/10.Messi has been rated 10/10 in 114 games, scoring 250 goals and providing 85 assists.He has won 112 of these games, drawing one and losing one, which was vs Celta Vigo today. pic.twitter.com/ON71WECuvP— MessiTeam (@Lionel10Team) May 16, 2021"It would be impossible to play without Lionel Messi" - Barcelona manager Ronald KoemanWhile facing a barrage of questions at the post-match press conference regarding Lionel Messi's future, Ronald Koeman made it clear that it would be impossible to play without him. “It would be impossible to play without him. But it’s Leo on his own and, to win more games and get more points, we need more players to score goals," Koeman said.Messi put in a 10/10 performance in Barcelona's defeat. (Photo by David Ramos/Getty Images)Koeman and the Barcelona hierarchy understand the importance of having the best player in the world in the squad. Koeman added that Lionel Messi's goals are vital to the club and have earned them a huge number of points singlehandedly. “Leo’s scored 30 goals and won us a lot of points. But [his future] is a question for him. For me and for the club, we hope he stays. Because if there’s no Leo, we have doubts about who will score the goals," Koeman said.Despite being 33 years old, Lionel Messi has proven time and again that he is still Barcelona's main man and holds the key for any future success for the Catalan giants.#BarcaCelta | "I hope this is not Messi's last game at the Camp Nou. He's still the best player in the world and he showed us again today that playing without him is impossible," Ronald Koeman said.#LionelMessi #Barca https://t.co/dCxrRaUQza— India Today Sports (@ITGDsports) May 17, 2021There was some optimism within the Barcelona camp when the club lifted the Copa del Rey that Lionel Messi would stay on for at least another year. However, after a disastrous end to the La Liga season which saw Barcelona fall behind both Madrid clubs in the title race, Messi's future is again up for debate.If Lionel Messi doesn't renew his contract, the game against Eibar could be his last outing for Barcelona.