** FILE ** In this Wednesday, Jan. 22, 2014, file photo, recruiter Valera Kulow, left, speaks with job seeker Monic Spencer during a career fair in Dallas. (AP Photo/LM Otero, File)
Dallas Mavericks' Dirk Nowitzki (41) shoots from the perimeter over San Antonio Spurs' Tiago Splitter (22) in the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
San Antonio Spurs' Tony Parker (9) attempts to get around the defense of Dallas Mavericks' Jose Calderon and Dirk Nowitzki, right, during the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
San Antonio Spurs' Patty Mills, left, is knocked back by Dallas Mavericks' Jose Calderon as Calderon loses control of the dribble in the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
San Antonio Spurs' Tim Duncan (21) loses control of the ball after being fouled by Dallas Mavericks' Dirk Nowitzki (41) beneath the basket as Samuel Dalembert (1) and Tiago Splitter (22) watch in the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
Dallas Mavericks' Vince Carter (25) shoots as San Antonio Spurs' Marco Belinelli (3) and Tiago Splitter (22) defend during the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
San Antonio Spurs' Tim Duncan (21) goes up for a shot over Dallas Mavericks' Dirk Nowitzki (41) as Tiago Splitter (22) watches in the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
Dallas Mavericks' Monta Ellis (11) looks for an opening to the basket as San Antonio Spurs' Tim Duncan defends in the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)
San Antonio Spurs' Manu Ginobili (20) goes up for a shot as Dallas Mavericks' Dirk Nowitzki (41) defends in the first half of Game 4 of an NBA basketball first-round playoff series, Monday, April 28, 2014, in Dallas. (AP Photo/Tony Gutierrez)