Tournament officials and Sampras' agency, IMG, said on Thursday that Sampras would not be featuring in the event --- the fifth straight tournament he has withdrawn from.
Sampras, who has not played a tournament since winning the 2002 U.S Open last September, has pulled out of all five events he had entered this year - San Jose, Scottsdale, Indian Wells, Miami and now Houston.
Last week, the seven-times Wimbledon champion asked for a wild card into the Queen's Club grass court tournament, which is played the week before Wimbledon.
However, his brother Gus said Pete's Queen's request was not a solid indication that
he will come back.
"It's just standard business," Gus said. "He hasn't made up his mind whether he'll return."
U.S. Davis Cup captain Patrick McEnroe said he spoke with Pete Sampras in March
and feels he will play Wimbledon.
"But he doesn't know -- nobody knows," McEnroe said. "He seems perfectly happy doing what he's doing right now."
McEnroe added that if Sampras returns he'll have a great shot at his eighth Wimbledon title.
"After what I saw at Flushing Meadows last year, nothing will surprise me," said McEnroe.
"He can show up at Queen's and win two matches and then lose, play one exhibition, and if he wins two rounds at Wimbledon, everyone in the locker room is going to be shaking in their boots."