Advocate staff photo by HILARY SCHEINUK -- LSU second baseman Jared Foster makes a throw to first during a game against Texas A&M on April 25 at Alex Box Stadium. Foster, a senior who started 40 games this season, is academically ineligible.

Jared Foster has played his last game for LSU.

Foster, the Tigers’ senior starting second baseman, has been ruled academically ineligible and will not rejoin the team this season, putting an end to his four-year LSU career.

“I’m just disappointed,” coach Paul Mainieri said.

Foster was in the midst of his most productive season following a year in which he hit .115. He’s batting .275 with eight home runs, tied for the team lead. He’s got a .506 slugging percentage.

Foster played in all three games at Mississippi State last weekend. Final exams were this week, but all grades have not been released. Foster would have been ineligible starting next week, according to NCAA rules.

“I decided to implement it right away and go with the players that are going to be with us for postseason and get them as much playing time,” Mainieri said.

His absence creates an issue for the consensus No. 1 team in the nation. LSU (41-8, 17-7 Southeastern) is already down backup second baseman Kramer Robertson, out at least two more weeks with an elbow injury. Robertson started the season at second before a demotion.

Danny Zardon, who started the season at third base before errors cost him that job, replaced Foster in the lineup for the series-opening 8-3 win over Missouri (28-22, 14-11). The news on Foster was released about an hour before first pitch.

Zardon played error-less at second and hit a home run. Mainieri said he “may stick” with Zardon at second base.

Conner Hale, who moved from second base to third earlier this season, is an option as well.

“I’m going to go with what I think is the better defensive team out there,” Mainieri said. “Right now, I think the best defense is Zardon and Hale. The only question is whether or not Hale should go to second and Zardon to third. Just because of the lateness of everything (Friday) I just didn’t want to start moving guys all over the place.”

Foster, who has mostly played left field during his college career, began this season lightning hot at the plate. To keep him and left fielder Jake Fraley in the lineup at the same time, Foster was moved from the outfield to second base — a position he hadn’t played since high school.

He had 40 starts in LSU’s first 48 games. He has made eight errors for a .957 fielding percentage.

Foster, a Lake Charles native, walked on to the football and baseball teams at LSU before dropping the former. He rejoined the football team last summer, called by offensive coordinator Cam Cameron in a recruiting pitch to be a reserve quarterback.

He injured his foot during fall camp, a lingering injury that needed minor surgery.

Foster had slipped recently at the plate.

He was 5 for his last 29 and he hadn’t hit a homer in 14 games. His batting average had dropped by 52 points over the last six weeks.

He was still a key player on a squad that most expect to claim a top eight NCAA national seed.

Follow Ross Dellenger on Twitter: @DellengerAdv.