LeBron James is widely regarded as one of the greatest basketball players of all time. The 35-year-old has reached nine NBA Finals, which is the most by any player this century. James becomes virtually unbeatable when he activates 'Playoff Mode'.LeBron James' 5 worst playoff performancesThough LeBron James is among the most successful playoff players of this era, he's had his fair share of failures in the postseason as well. In this article, we'll take a look at five such instances when LeBron James came up small in the postseason.Before we begin, it should be noted that LeBron James might have had worse games statistically. But we'll consider the context around the series, the pressure and the historical significance of the defeat while compiling this list.#5 Game 6 NBA Finals against Dallas Mavericks (2010-11) Dallas Mavericks vs Miami Heat - Game SixThe expectations were sky high from the Miami Heat before the commencement of the 2010-11 NBA season. That was because soon after leaving Cleveland, LeBron James had announced publicly that he would win multiple championships along with Dwyane Wade and Chris Bosh in the coming years.Dirk. Showed. Out. 😤Film Room: Mavericks vs. Heat, 2011 NBA Finals Game 6 - 3pm ET on NBA TV! pic.twitter.com/aDIP9fkZNu— NBA TV (@NBATV) June 16, 2020Though LeBron James had a decent game on paper with 21 points, six assists and four rebounds, Miami was '-24' in plus/minus when he was on the floor.With this defeat to the Dirk Nowitizki-led Dallas Mavericks, LeBron James went 0-2 down in NBA Finals and was heavily criticized for not being able to win the title despite moving to a better team.#4 Game 4 NBA Finals against Golden State Warriors (2017-18)2018 NBA Finals - Game FourThis was the most recent NBA Finals King James was a part of.After falling to the Golden State Warriors in five games in 2017, fans were expecting a better fight from the Cleveland Cavaliers against Steph Curry's Warriors in the 2018 rematch.The @warriors take Game 4 and are the 2018 NBA Champions!GSW defeats @cavs 108-85 to win the #NBAfinals!Stephen Curry: 37 PTS, 7 3PMKevin Durant: 20 PTS, 12 REB, 10 ASTDraymond Green: 9 PTS, 9 ASTKlay Thompson: 10 PTS, 6 REB#DubNation #ThisIsWhyWePlay pic.twitter.com/ZZn7H2ub5x— NBA (@NBA) June 9, 2018However, things turned out to be even worse for LeBron James and the crew as they were swept in four straight games by the Warriors this time. LeBron James' worst performance of the series came in Game 4 where he ended up with 23 points, six turnovers and five fouls.Also read: NBA Trade Rumors: Phoenix Suns might be tempted to move Kelly Oubre Jr. in return for the Golden State Warriors' No. 2 draft pick.