Trapped in another losing season, the suddenly last-place Lakers can find some solace in the knowledge that their star point guard could be back on the court this week. Lonzo Ball was cleared Tuesday to return to practice after missing the last five games with a left shoulder sprain. Coach Luke Walton has long said that Ball is the key to the Lakers’ identity, and indeed, they have been unable to win without him since he suffered the injury on Dec. 23. They are on a season-worst seven-game skid and the five losses without Ball have been by an average of 13.2 points. Ball is averaging 10 points, 6.9 rebounds and 7.1 assists per game and is the instigator of the Lakers’ offense and the motor to their pace of play, a category in which they lead the league.