The Vikings defensive backfield keeps taking hits.

Starting cornerback Josh Robinson left Sunday's 41-20 loss at Seattle because of a fractured sternum and will miss at least a month.

All four starters in the secondary have missed games this season. Safety Harrison Smith (turf toe) is on injured reserve/designated for return and is expected back for the final three games of the season. Robinson, with six games remaining, could go on injured reserve and be lost for the season; coach Leslie Frazier said that option would be discussed.

Frazier said the injury occurred on a first-half tackle, and Robinson continued to play but was having problems catching his breath.

"We decided not to let him continue until we got a look at it, and found out today he suffered a fracture," Frazier said.

Xavier Rhodes likely will replace Robinson as the starting left cornerback, and Marcus Sherels would replace Rhodes at nickel back.

Robinson, a second-year player from Central Florida, had 58 tackles and one forced fumble this season.

Sunday surprise

Frazier was surprised wide receiver Greg Jennings didn't suit up against the Seahawks. Frazier listed Jennings as probable Friday while dealing with an Achilles' tendon injury, but Jennings was inactive Sunday.

"There was nothing in my mind that made me think on Friday that he wouldn't be able to go," Frazier said. "It wasn't until maybe Saturday night when I talked to him right before our team meeting that I got a hint that there was a potential chance that he might not be able to go, and even then I thought he'd be fine when he got up the next day. … Just wasn't able to do it, so we had to scratch him. That was a tough one because we did expect him to be able to play."

Cordarrelle Patterson and Jarius Wright started at wide receiver for Jennings and Jerome Simpson, who received fewer snaps following his drunken-driving arrest on Nov. 9.

Patterson was targeted nine times and had three catches for 28 yards. He played in 43 of the team's 74 snaps on offense. Wright had three catches for 69 yards and two touchdowns and led the unit with 48 snaps.

"It was good for [Patterson] get the snaps that he got and to come up with the catches that he made," Frazier said. "We targeted him more than we actually got the ball to him. They did some good things coverage-wise as well, but I thought overall he did a good job."

Waiting game

Center John Sullivan left the Seattle game because of a concussion and must pass the NFL-mandated tests before he is cleared for Sunday's game at Green Bay.

Sullivan, a six-year veteran, has 36 consecutive starts (including playoffs) for the Vikings, dating to Oct. 30, 2011, against the Panthers. Sullivan has missed only three games in his career.

Running back Adrian Peterson was bothered by a groin injury and had only 65 yards on 21 carries.

"I need to talk with our medical staff, our trainers a little bit more, but my understanding is he should be ready to go," Frazier said, "but I still need to get some other information."

Trouble for Fowler

Vikings minority owner Reggie Fowler faces unpaid debts of nearly $60 million, according to The Arizona Republic. Fowler's Arizona-based company, Spiral Inc., holds or has held more than 100 businesses, and is now in receivership. Its headquarters has shut down, the newspaper reported.

Fowler, 54, is one of six partners in the Vikings ownership group. He tried to buy the team as majority owner in 2005, but couldn't meet the NFL's financial requirements, and ended up as a minority owner when Zygi Wilf bought the team from Red McCombs.

Etc.

• Receiver Greg Childs, on the physically unable to perform list after tearing both patellar tendons in training camp in 2012, tweeted Monday that he was returning to practice with the Vikings on Wednesday.