Paul Mainieri’s rebuilding effort just got a little tougher.

Infielders Grayson Byrd and Danny Zardon are transferring, the LSU baseball coach confirmed Monday night.

Zardon, a rising junior who never found an everyday role in the lineup, is leaving the Tigers for Nova Southeastern, an NAIA school in Florida where he’ll be eligible immediately. Byrd doesn’t know where he’s transferring, said Paul Byrd, Grayson’s father and a former LSU star pitcher who spent 14 seasons in the major leagues.

Mainieri and staff will have to rebuild their starting lineup without two of the Tigers’ top reserves. Byrd hit .212 and played in 24 games, starting two at third base and two at second base. Zardon, who had a game-winning double against Texas A&M, served in a pinch-hitting and designated hitter role much of the season. He lost his starting job at third base after an error-filled first few weeks of the season. He ended up hitting .288.

LSU lost seven of eight everyday starters from a squad last season that advanced to the College World Series.

The Tigers will welcome 14 newcomers this year — several of whom could see immediate playing time. In an extensive postseason interview with The Advocate, Mainieri said LSU could start the 2016 season with as many as three or four freshmen in the lineup.

Trey Dawson, a highly rated prospect from West Virginia, is expected to compete to replace Alex Bregman at shortstop.

St. Thomas More infielder O’Neal Lochridge is expected to get cracks at several infield spots. Former Delgado star Cody Ducote and Lafayette’s Antoine Duplantis are possibilities to play in the outfield.

The school plans a news conference for Thursday to introduce the signing class.

“We’ve got a big rebuilding project to do this fall,” Mainieri said. “You want to have players committed to our program. We’re going to go with the guys we have.”

Mainieri said he was surprised by the transfer of Byrd, who called him recently to break the news. Byrd didn’t complete his summer ball season after suffering a sore arm. Mainieri said he didn’t make coaches aware of the injury until recently; he visited his own doctor.

“The Grayson Byrd situation has surprised me,” Mainieri said. “That call came out of left field.”

Mainieri met with Zardon this summer to discuss his status as a starter. The coach said Zardon and he “both agreed the best thing for him is to go somewhere where he’ll need to be in the lineup every day.”

Mainieri couldn’t promise Zardon a starting spot. The coach started Zardon at third base to begin last season before a host of fielding miscues. Zardon moved to first base and then slipped from the lineup completely, becoming LSU’s designated hitter against left-handed pitchers.

“Some schools will afford that kind of guarantee to a youngster, and I just can’t,” Mainieri said of a starting spot. “I hope he does well and gets his chance at professional baseball.”

Follow Ross Dellenger on Twitter: @DellengerAdv.