An already thin UCLA offensive line currently without a position coach is now down its left tackle.

Niki Prongos, who was put on scholarship in late September and started eight games before suffering a season-ending injury, entered the transfer portal Monday.

Rivals national transfer portal analyst and rankings director Adam Friedman confirmed the news first reported by Bruin Report Online.

Prongos opened the season as the Bruins’ top reserve, filling in at right tackle for injured starter Garrett DiGiorgio in the season opener at Hawaii.

Then, Prongos started the third and fourth game of the Bruins’ season at right guard, taking over for struggling UNLV transfer Alani Makihele.

Finally, UCLA switched things up once more in an Oct. 5 road contest at Penn State. Prongos became the Bruins’ permanent left tackle, taking over for Houston/Louisville transfer Reuben Unije, while freshman Sam Yoon took over at center and Josh Carlin moved over to right guard.

Prongos made five starts at left tackle before suffering a season-ending injury Nov. 8 against Iowa.

UCLA, which also lost Carlin and left guard Spencer Holstege to graduation, will look to restock the five-man unit — but under new guidance. Offensive line coach Juan Castillo was not brought back for a second season after the program fired offensive coordinator Eric Bieniemy.

The Bruins have yet to announce a successor as the program also awaits the arrival of new offensive coordinator and current Indiana co-coordinator/quarterbacks coach Tino Sunseri, who will finish out the College Football Playoff run with the Hoosiers before reporting to Westwood.

UCLA’s dire situation along the offensive line was due in part to injury, with third-string backup Jaylan Jeffers and fourth-string Yutaka Mahe each forced into action at the end of the season.

In all, 15 UCLA players have announced their intention and/or entered the portal since the end of the regular season. The portal officially opened for business Monday.