The 32-year-old basketball player - who arrived from the Los Angeles Lakers in December - has come under fire from supporters for a number of poor performances this season, which insiders believe are down to the pressure of his celebrity lifestyle and being in front of the cameras on reality TV show 'Khloe and Lamar'.
An NBA (National Basketball Association) source told the New York Post newspaper: ''When he wasn't playing well, it meant he looked bad.
''And when you have a show about your life, when you are off-court, you have to deal with the producers asking all those questions. He had a horrible summer, but ... he was more concerned about the cameras and how he looked.''
Lamar - who took a leave of absence in February after his father fell ill - confirmed in a statement: ''The Mavericks and I have mutually agreed that it's in the best interest of both parties for me to step away.''
But Khloe - who relocated from Los Angeles to Dallas in December and got a job as a radio host, presenting 'The Mix Up With Khloe Kardashian Odom' on MIX 102.9 - has pledged her support to the basketball star and admitted she will ''miss'' the city.
In a series of tweets, the 27-year-old brunette wrote: ''Never a dull moment.
''U deserve so much better. Know ur worth and know ur skills that have been proven and earned! U showed ur strength, I love u.
''Blessed to have had such an amazing experience. Short but very sweet :) #memories
''I loved Dallas and will miss it! (sic)''
Lamar will be listed as inactive, rather than being immediately released, allowing the Mavericks to trade him when the season ends in June.
During his Mavericks career Lamar averaged less than seven points a game, but he managed an average of more than 14 points a match with the Lakers last season.