The sixth seed, Felix Mantilla, advanced to the quarter-finals with a walkover and Becker also withdrew from the doubles, where he has been partnering Henman.
Becker felt the injury in Wednesday's doubles victory over the Spaniards, Alex Corretja and Javier Sanchez, and the abdominal strain failed to respond to heat treatment and massage.
The defending champion Thomas Muster paid the price for a long break at the end of last season when he was beaten 7-6, 6-4 by the emerging German, Nicolas Kiefer.
Kiefer was until recently a member of Becker's squad of promising young players, before striking out on his own with the German's old coach, Bob Brett.
Andre Agassi, the former world No 1, showed that he is still a force to be reckoned with after taking just 41 minutes to beat Gustavo Kuerten, the French Open champion, 6-3, 6-1 in the second round of the Sybase Open in San Jose yesterday.Reuse content