The San Francisco 49ers held four training camp practices last week, marking up the beginning of their final offseason phase.
RELATED: Full Recap of 49ers Training Camp Week 1: Offense
Here's a recap of what I saw and the initial review of every position group on the defense
Defensive Line
As expected, the defensive line dominated during the first week of training camp.
Nick Bosa stood out, getting to the quarterback on nearly every day, including a sack against right tackle Mike McGlinchey on Saturday.
Rookie Drake Jackson stood out on Thursday, earning a sack, and even got some first-team reps opposite of Bosa.
The underrated player has been newly-signed Robert Nkemdiche, who has been a disrupter against the second and third-team defense. While originally seeming like a camp body, Nkemdiche could fight for a roster spot after the recent injuries to defensive linemen on the 49ers.
After Arik Armstead sprained his MCL on Wednesday, defensive tackle Kevin Givens has been taking the first-team reps alongside Javon Kinlaw, and has flashed as a pass-rusher as well.
Linebackers
Fred Warner, Azeez Al-Shaair, and Dre Greenlaw were all back on the practice field to start training camp, while Al-Shaair was the linebacker taken off during nickel packages.
The name to watch is backup linebacker Curtis Robinson, who's been the MIKE linebacker with the second-team defense, and has been a vocal leader with the unit. He's a sleeper candidate to make the 53-man roster.
Of the three undrafted free agent linebackers, Marcelino McCrary-Ball has been an early standout, as his quickness and coverage were exhibited while covering running back Tyrion Davis-Price on a wheel route on Saturday.
He's also been an alert player in the run-game, cutting off speedy receiver Danny Gray on a jet-sweep for four yards.
Cornerbacks
Top cornerbacks Charvarius Ward and Emmanuel Moseley have been excellent, arguably being the two-best defensive players for the 49ers.
Of the backups, Deommodore Lenoir has been a pleasant surprise, moving well in coverage, working exclusively on the outside, and being the third-best cornerback thus far, despite having his roster spot questioned by many in the offseason.
Ambry Thomas has had an up-and-down camp, but the 49ers finally allowed him to play press-man coverage on Saturday, which resulted in a holding penalty against receiver Malik Turner running a go-route, but also a beautiful rep against Danny Gray on a comeback.
Additionally, rookie Tariq Castro-Fields has looked the part of an NFL-esque cornerback thus far, playing primarily on the outside as I suggested, as opposed to the slot reps that he had in OTAs and minicamp.
Lastly, veteran Darqueze Dennard took a majority of the first-team reps at slot cornerback last week, although he was replaced by Dontae Johnson as a starter on Saturday, bumping him down to the second-team defense.
Rookie cornerback Samuel Womack, who had been taking all of the second-team reps in the slot, was moved to the third-team defense as a result.
Safeties
Starting safeties Jimmie Ward and Talanoa Hufanga had strong performances during Week 1, with the former picking off Trey Lance, while the latter recorded a nice pass-breakup on a pass intended for Ray-Ray McCloud by Lance.
Backup safeties Tarvarius Moore and George Odum have looked good too, with the former recording two interceptions on Saturday, while the latter has been around the ball on a good amount of plays.
Those four players are the most likely candidates to make the 53-man roster.
Dontae Johnson, who was taking third-team safety snaps with rookie Leon O'Neal, was moved to slot cornerback on Saturday, as mentioned above.