At the halfway mark of the preseason, teams are getting a pretty good grasp on the potential of their first-year players. Two games worth of film provide coaches with a decent sample size to evaluate how their rookies fare during live action.
Pro Football Focus has taken note of three San Francisco 49ers rookies who have turned heads so far. Here's a look at what PFF had to say regarding some of the 49ers promising young talent.
Dante Pettis
The 49ers second-round pick had a standout training camp. Pettis has flashed with his speed and his ability to get open in coverage. He broke free and nearly caught a 63-yard touchdown on an overthrown pass by C.J. Beathard against the Houston Texans last Saturday. He has amassed 85 yards over the first two preseason games, headlined by a 53-yard reception against the Dallas Cowboys.. PFF recognized Pettis as one of the under-the-radar rookies to watch out of the NFC West.
"Pettis is already making a name for himself among coaches and players in his first 49ers training camp. The former Washington wide receiver is a smooth route-runner with reliable hands that has the ability to develop into a security blanket for quarterback Jimmy Garoppolo.
"Pettis has the good fortune to develop behind veteran Pierre Garçon who finished tied for first in the NFL in drop rate with zero drops on 40 catchable targets before an injury ended his season. If Pettis can continue his positive momentum this preseason, he should be able to carve out a role in multi-receiver sets in San Francisco this season."
View every player currently on the San Francisco 49ers 2018 90-man roster.

DL Arik Armstead

DL Jeremiah Attaochu

QB C.J. Beathard

DL Ronald Blair III

WR Victor Bolden Jr.

WR Kendrick Bourne

RB Matt Breida

DL DeForest Buckner

WR Aaron Burbridge

TE Garrett Celek

DB Adrian Colbert

G Jonathan Cooper

LB Brock Coyle

DL Sheldon Day

WR Steven Dunbar Jr.

TE Ross Dwelley

DB Antone Exum Jr.

OL JP Flynn

LB Reuben Foster

WR Pierre Garçon

RB Ja'Quan Gardner

G Joshua Garnett

QB Jimmy Garoppolo

OL Garry Gilliam

WR Marquise Goodwin

G Chris Gonzalez

K Robbie Gould

S Marcell Harris

QB Jack Heneghan

TE Cole Hikutini

WR Richie James

FB Malcolm Johnson

DT Chris Jones

DL D.J. Jones

FB Kyle Juszczyk

TE George Kittle

OL Andrew Lauderdale

LB Elijah Lee

P Jeff Locke

CB Greg Mabin

OL Erik Magnuson

DL Cassius Marsh

WR Max McCaffrey

CB Tarvarus McFadden

DB Dexter McCoil

T Mike McGlinchey

RB Jerick McKinnon

RB Jeremy McNichols

NT Earl Mitchell

DB Tarvarius Moore

RB Alfred Morris

CB Emmanuel Moseley

RB Raheem Mostert

QB Nick Mullens

T Pace Murphy

LS/TE Kyle Nelson

LB Mark Nzeocha

OL Mike Person

WR Dante Pettis

P Bradley Pinion

DB Tyvis Powell

CB D.J. Reed

C Weston Richburg

WR Aldrick Robinson

TE Wes Saxton

DL Niles Scott

OL Coleman Shelton

CB Richard Sherman

LB Malcolm Smith

T Joe Staley

DL Kentavius Street

DL Will Sutton

S Jaquiski Tartt

LB Pita Taumoepenu

DT Jullian Taylor

WR Trent Taylor

DL Solomon Thomas

OL Laken Tomlinson

LB Korey Toomer

OL Najee Toran

DB Jimmie Ward

LB Fred Warner

LB Dekoda Watson

TE Cole Wick

OL Darrell Williams Jr.

RB Joe Williams

CB K'Waun Williams

RB Jeff Wilson

CB Ahkello Witherspoon
D.J. Reed Jr.
Reed is another rookie who has impressed in camp. The 49ers defensive back has taken on the challenge of learning both nickel corner and free safety while acclimating to the speed of the NFL. PFF revealed Reed at No. 7 on the top 10 rookie performances of the preseason.
"Reed is technically listed as a safety on the 49ers depth chart, but through two games he's taken 57 of his 75 snaps lined up as a slot cornerback. He's been targeted six times there and while he's allowed four catches, only one has gone for a first down while three have resulted in stops."
The 49ers first-round pick immediately stepped into the starting right tackle job. Thus far, McGlinchey has held his own against some of the NFL's elite in Dallas Cowboys' DeMarcus Lawrence and All-Pro lineman J.J. Watt during the team's joint practices with the Houston Texans. PFF has McGlinchey (64.1) graded higher than his fellow offensive linemen taken in the first round: Quenton Nelson (62.1), Kolton Miller (53.2), Billy Price (56.4) and Isaiah Wynn (44.5).
"The 49ers new right tackle has played 44 of his team's 143 offensive snaps so far this preseason and has graded out much better as a pass-protector (69.0 pass-blocking grade) than as a run-blocker (58.8 run-blocking grade). In two games, McGlinchey hasn't allowed a single pressure on any of his 26 pass-blocking snaps."