METAIRIE, La. -- The competition for New Orleans' third running back spot could get more intense in the next few days.
"We're looking right now, so I wouldn't say we're staying pat." Payton said. "We just haven't signed anyone in the last two days. Hopefully we're able to get someone in here that we have a high enough grade on."
One possibility is veteran running back Ladell Betts, a nine-year veteran who rushed for 1,154 yards for the Washington Redskins in 2006. Betts worked out for the Saints two weeks ago -- before Hamilton got hurt -- but was not signed.
New Orleans has lost almost half its running back carries from last season. Hamilton, who had 35 attempts in 2009, was expected to fill the role of Mike Bell, who signed with the Philadelphia Eagles in the offseason after rushing a team-high 172 times.
Bell was a short-yardage specialist, who had many of his carries as the Saints protected leads in the fourth quarter.
"Right now, to be fair to those two players, they have a lot of work ahead of them," Payton said. "Both of them have shown some real positive signs, but there's still a number of things that they're working on to get fully up to speed. I'd anticipate that we'll be able to get someone in here before the Texans' [preseason] game [next Saturday]."
Hill's and Ivory's lack of pedigree is not the issue. Thomas, who has led the Saints in rushing the past two years, was not drafted out of Illinois in 2007. Bell and Hamilton were undrafted free agents, too.
Hill's and Ivory's lack of experience is the concern.
Hill a three-time 1,000-yard rusher at Wisconsin, spent time on the practice squads of the Saints, Eagles and Washington Redskins as a rookie last year without being activated.
Hill had nine carries for 30 yards against New England on Thursday in the Saints' preseason opener. He also fumbled near the Patriots' goal line as he tried to fight for extra yards late in the fourth quarter.
Although he insisted his knee was down before the ball came loose, the play did not help his job security, particularly since he already had fumbled a couple of times during training camp. He bobbled a pitch in Sunday's practice.
"I can't make errors like that," he said. "I've got to be able to hold on to the ball. That's one of our first rules is protect the ball. I'll take that blame even if [the fumble against New England] came out late."
Ivory, who has earned Payton's praise more than once in training camp, faced long odds when he signed with the Saints. He rushed for 534 yards in three injury-filled seasons with Washington State, then transferred to Division II Tiffin University in his senior year.
He gained 227 yards in five games with Tiffin, which went 0-11, before a leg injury sidelined him again.
"He carries his pads well," Payton said. "He has good speed, and he's big and put well together."
Ivory carried six times for 30 yards with a 2-yard score against New England.
"I feel like I have the opportunity to play," he said. "That's why I came here. If [Thomas] came in as a free agent, I know I can do it, too. I think I have a good shot."
Backup free safety Usama Young sat out Sunday's practice with a groin injury. Payton said it was unclear when he would return or whether the injury was related to the sports hernia surgery Young had in December. ... The best play of Sunday's practice came on a 35-yard pass from Drew Brees to tight end Jeremy Shockey near the goal line. But backup safety Chris Reis, who was beaten despite having tight coverage, insisted Shockey did not get his feet inbounds. Rookie cornerback Patrick Robinson, a first-round draft pick, had two interceptions a day after defensive coordinator Gregg Williams criticized him. "Patrick has a lot of skill but right now he doesn't know how to play," Williams said. "Right now I don't have any trust in him. He has to take the next step up in pro football. He's had too much down time and he doesn't know how to take care of his body."