USC nose tackle Marlon Tuipulotu became the fourth Trojan in the last week to declare for the NFL draft, making the announcement Friday on Twitter.

It’s yet another big void to fill now on a USC defense that has also had star safety and Pac-12 Defensive Player of the Year Talanoa Hufanga and cornerback Olaijah Griffin announce their departures, not to mention defensive tackle Jay Tufele’s decision to opt out before the season.

Trojans left tackle Alijah Vera-Tucker also announced this week that he’s entering the draft.

Tuipulotu tallied 23 tackles, 3.5 tackles for loss, 2 sacks and a forced fumble in USC’s shortened six-game season this year.

The 6-foot-3, 305-pound three-year starter became a tone-setter for new coordinator Todd Orlando’s attacking defense as the anchor of a defensive line that was the strength of the unit all season.

Tuipulotu added some strong film to his resume this fall that should help boost his stock after he had played more in the shadow of Tufele in previous years. This season, he was a first-team All-Pac-12 selection.

At the front of that highlight reel will be his strip sack of Utah quarterback Cameron Rising that gave the Trojans possession at the Utes’ 4, leading to their first touchdown in that game.

This was an expected loss for the USC defense, but it will be a tough one to replace. Senior Brandon Pili would be the logical successor at that nose tackle spot, while the Trojans other interior defensive line depth is mostly unproven.

Redshirt junior Nick Figueroa is versatile and can play multiple roles up front, but freshman Kobe Pepe, redshirt freshmen De’jon Benton and Stanley Ta’ufo’ou and freshman Jamar Sekona have minimal experience. USC also signed 4-star DT Jay Toia and landed former 4-star DT Ishmael Sopsher as a transfer from Alabama, where he did not see much playing time.

USC largely operated out of a three-down front this year with Tuipulotu, Figueroa and younger brother Tuli Tuipulotu (at defensive end) the key cogs by the end of the season, with Pili and veteran DE Caleb Tremblay also in the mix throughout the year.

It will officially be known Saturday if USC landed 5-star DE Korey Foreman, who is announcing his college choice (he’s already signed with a school) during the All-American Bowl live show on NBC. If the Trojans get him, they will want to find a way to get their pass rushers on the field in some combination of Foreman, the younger Tuipulotu and outside linebackers Drake Jackson and Hunter Echols, while Figueroa has certainly earned a role after his strong 2020 season. But in terms of having a true nose tackle, Pili is the logical fit, but he played a much smaller role this year and would have to prove still that he could handle a much larger workload.

Meanwhile, USC is still waiting to see what wide receivers Amon-Ra St. Brown and Tyler Vaughns decide about their futures.