Defensive tackle Kevin Williams and defensive end Ray Edwards missed their second straight practice on Thursday because of knee trouble.
The outlook does appear positive for Williams, at least. NFL Network's Jason La Canfora reports Williams is highly likely to play, according to a source with knowledge of the situation. The team will remain cautious with Williams, who has a bone bruise on his knee, according to La Canfora.
"They're improving," defensive coordinator Leslie Frazier said of Williams and Edwards. "We're hoping we can get some work out of them today, at the latest tomorrow. But, they're both improving."
Receiver and kick returner Percy Harvin also was not present Thursday. After practicing on Wednesday, he got another migraine headache, a problem that has plagued him all season.
Harvin missed a game against Cincinnati in December because of the headaches and visited the Mayo Clinic to address the recurring issue. While Harvin has been headache-free for more than a month, coach Brad Childress said it was unrealistic to think that the problem had been solved.
"I think it's just a matter of trying to slow the onsets," Childress said. "For a while he had them pretty often. This is the first time one's raised up (in a while). We expect him to be OK."
"We're trying to put Percy in as many places as we can," offensive coordinator Darrell Bevell said. "We want to make sure we don't have him just lined up in one spot where you can take him away. ... It's important to get the ball in his hands, sometimes to throw it (to him) and sometimes the easiest way is just to hand the ball to him."
Edwards had three sacks and five quarterback hurries in last weekend's win over Dallas and Williams is a perennial Pro Bowler and one of the league's best defensive tackles. Williams is a force against the run and also provides pressure on the quarterback up the middle.
If the Vikings are going slow down the league's highest scoring offense in New Orleans, Williams and Edwards figure to play a big part in it.
"They are vital cogs to our success on defense," Frazier said. "So we need the both of them. You'd like to have them at 100 percent. Not sure if that will be the case. But just their presence will make a difference."
Winfield said he still expects to spend most of his time against the Saints' high-flying offense on Sunday lined up as the nickelback in the slot. The Vikings made that adjustment -- and move nickelback Benny Sapp outside -- when Winfield returned to reduce the stress on his foot as we worked his way back.
For the first time on Thursday, Winfield acknowledged his foot was fractured, and not sprained, against Baltimore on Oct. 18.
"Once I fractured my foot, I really couldn't condition, really couldn't lift (weights) with my lower body," Winfield said. "The last couple weeks, I feel myself getting my strength back and getting close to 100 percent."
The Associated Press contributed to this report