EAST LANSING — Michigan State 's revolving door at left tackle continues to spin going into Big Ten play. Kevin Jarvis, who suffered an apparent right knee injury against Arizona State, will not play Saturday when the Spartans travel to Northwestern for the conference opener for both teams. Coach Mark Dantonio said Jarvis is expected to miss at least six weeks but hopeful to return by November. "I would expect back maybe by Penn State (Oct. 26), or for sure, November," Dantonio said Tuesday during his weekly news conference. "So he's not a season-lost guy, but I thought it would be period of time not to have him on the depth chart." MSU (2-1) already is without senior Cole Chewins (back) and junior A.J. Arcuri (right foot) , who were projected to be the top two left tackles going into the season. "Cole and A.J., probably remain the same," Dantonio said. "They are both sort of day-to-day. I would just say right now, they are out (this week), day-to-day." Jarvis got blocked backward over an Arizona State defender with 1:10 left in the second quarter of Saturday's 10-7 loss at Spartan Stadium , grabbing his right knee as he landed but walking to the locker room without help from trainers. The 6-foot-4, 307-pound junior had played right guard exclusively before this season, moving to left tackle before the opener against Tulsa because of the injuries to Chewins and Arcuri. Jarvis also missed four games after injuring the same knee at Indiana last season. The Chicago native started the first three games this season at his new position. Senior Tyler Higby , who started three games at left tackle last season and took over for Jarvis against the Sun Devils, is listed as the starter. Devontae Dobbs is listed as the backup, one of three true freshmen making their first appearance on the depth chart. J.D. Duplain is the No. 2 left guard behind Luke Campbell, while Nick Samac is the backup to Jordan Reid at right tackle. Redshirt freshman Jacob Isaia is the No. 2 right guard behind Matt Carrick. Dantonio said the three true freshmen have been working exclusively with the No. 2 offense early in the season. He would not commit to their playing status against the Wildcats (1-1). "I think those guys are prepared," Dantonio said. "And whether they play this week or not will remain to be seen, depending on how we are playing, depending on injuries and things of that nature. ... They are getting ready." Dobbs, a highly touted four-star recruit from Belleville who did not enroll early as Samac and Duplain did, made his debut in the fourth quarter of MSU's 51-17 win over Western Michigan on Sept. 7 . He played left tackle and was in for a late touchdown. Dantonio said the decision to go with Higby over Dobbs right now is "knowledge-based and youth-based, a combination of both." "I thought Higby went in there and played pretty well from everything that was given to me and indicated to me. So he's first man up," he said. "But I would expect for Dobbs to possibly play, and you know, he's got to get ready to play. So there will be a little bit more sense of urgency, maybe, is what I would say. "You know, when you're playing, it's different. When you get in the game, all of a sudden everything becomes a little bit more important in practice. We're going to push the issue there a little bit, especially on the depth chart, so that they understand that." The Spartans battled a number of nagging injuries on the offensive line last season, with 19 games missed by the five projected preseason starters in 2018. They also used five punters a year ago . Contact Chris Solari at csolari@freepress.com . Follow him on Twitter @chrissolari . Read more on the Michigan State Spartans and sign up for our Spartans newsletter .