“He’s been playing very, very well and did an outstanding job, too,” Dantonio said.

The injury is another entry on a long list of health troubles Jones has encountered as a Spartan. He missed eight games in 2011 with a torn Achilles and missed the final six games of the 2012 season with an injury.

Converted from safety just before this season, Jones’ athletic ability and defensive back skills have allowed him to thrive in spot duty for MSU. Through four games, Jones has 12 tackles, one for loss, a pass breakup and a team-leading two interceptions.

Jones came up with MSU’s first turnover of the year on the first possession of the season opener when he intercepted a Western Michigan pass and quickly lateraled to junior safety Kurtis Drummond, who ran it in for a touchdown.

The Spartans are the nation’s top statistical defense, allowing 188.8 yards per game. For comparison, the No. 2 defense belongs to Florida, which allows 212.3 yards per game.

Jones got his first start of the season against the Fighting Irish in place of junior linebacker Taiwan Jones, who was hobbled against Youngstown State but was good enough to finish the Notre Dame game.

Dantonio also revealed senior safety Isaiah Lewis had knee surgery on Sept. 12 before the Youngstown State game, which explained why Lewis played sparingly against the Fighting Irish. Sophomore R.J. Williamson started in his place and notched a team-high 10 tackles.

“We need (Lewis) for the Big Ten season,” Dantonio said. “… He probably could have played in the game at safety, but we felt like we needed to hold him.”

Six weeks tentatively sidelines Jairus Jones until the Nov. 2 game against Michigan. The Spartans have their second bye week after the U-M game to prepare for Nebraska, so he could have extra time to heal if necessary.

Taiwan Jones, the usual starter at the “star” linebacker, is expected to remain in the lineup in Jairus Jones’ absence. The Jairus Jones’ quickness and coverage prowess could have proved especially helpful in upcoming matchups with Indiana and Illinois’ spread offenses.

Fortunately for MSU, linebacker is one of its greatest positions of depth with talented sophomores Darien Harris and Ed Davis as well as senior Kyler Elsworth waiting in the wings.

Dantonio once again went to his secondary to fill the hole at linebacker by converting junior safety Mylan Hicks to the star spot, he told reporters on a conference call Tuesday. Hicks previously was listed as the third-string free safety on the depth chart.