EAST RUTHERFORD, N.J. -- Andrew Thomas' introduction to the NFL came from the fierce pass-rushing quartet of T.J. Watt, Bud Dupree, Khalil Mack and Robert Quinn. Not exactly the most accommodating welcoming committee.

It was supposed to get easier in Week 3 for the New York Giants' left tackle with San Francisco's Nick Bosa out for the season. But it wasn't. Thomas allowed four more pressures against an injury-ravaged 49ers defensive line.

More confirmation that life as a rookie, especially on a struggling line, is difficult. Even if you're the No. 4 overall pick.

"As a rookie, you deal with the ups and downs," Giants offensive line coach Marc Colombo said.

Thomas, who limped off with a leg injury late in last week's loss to the 49ers but is expected to be fine for Sunday's game (4:05 p.m. ET, Fox) against the Los Angeles Rams, is a more than respectable 20th among offensive tackles with a 77.3% run block win rate, according to ESPN's metrics using NFL Next Gen Stats. The downs have been more evident in pass protection. His 80% pass block win rate ranks him 149th out of the 167 qualifying linemen and 52nd of 65 offensive tackles.

Pro Football Focus has Thomas with a 55.5 grade overall, which ranks him 66th out of 71 offensive tackles. He has allowed 13 pressures and one sack in 137 pass-block snaps. The 13 pressures are the most allowed by a rookie tackle this season through three games.

The quiet and serious Thomas knows there is room for improvement. By all accounts, he has been unfazed by the early returns.

"The biggest thing I have been working on is just my hands in pass [protection]," Thomas said. "Being more consistent with them with my strength and my punch, that's something that I'm still working on. I made improvements but I'm still trying to get better every day."

Thomas insists he hasn't been overwhelmed by the speed and strength of his opponents. It's more the refined techniques of his opponents that have been eye-opening. This is the difference between the talented SEC pass-rushers he faced for three years at the University of Georgia compared to the All-Pros he has seen early this season.

It hasn't helped that Thomas has been thrown straight into the fire without an offseason or preseason games. Being the first offensive lineman selected, he isn't afforded the opportunity to sit and develop like the Giants' third-round tackle, Matt Peart, or fifth-round guard, Shane Lemieux. Thomas can't even get eased in at right tackle (the original plan) because veteran Nate Solder opted out of playing this season.

Then came Watt and Dupree in a Week 1 loss to the Pittsburgh Steelers. Mack and Quinn were next in a Week 2 loss to the Chicago Bears.

"Not everything has been perfect. This guy is learning, but he's really competing and he's progressing," Giants coach Joe Judge said last week. "This guy has the ability to be a really good player in this league for some time."

What has been evident is Thomas isn't an immediate savior for an offensive line that has been a liability for years. The Giants are scoring 12.7 points per game (31st) and are last in the league averaging 56.7 yards on the ground.

This is hardly an indictment on Thomas alone. The Giants are starting a rookie left tackle in addition to a first-time center (Nick Gates) and offseason acquisition Cameron Fleming at right tackle while guards Kevin Zeitler and Will Hernandez have been disappointingly pedestrian. It's a new group at a position where continuity is considered imperative.

The Giants hope their patience pays off. Their next three opponents -- the Rams on Sunday, Dallas Cowboys the following week and the Washington Football Team -- currently have bottom-half-of-the-league run defenses.

This should give Thomas and the rest of the offensive line a better chance.

"Being a rookie first-round pick -- I was there as a player -- he's had some really good pass-rushers he's going against," Colombo said. "We haven't run the ball really well, so we're dropping back to pass quite a bit and I think he's handled himself well for the most part. Across the board [for the offensive line], it's really just inconsistent play."

Not exactly what the Giants wanted to see. But maybe it should have been expected. The Giants still aren't wavering, though. Thomas has impressed Judge.

"The athleticism always stands out with him, whether it was the tape coming out of Georgia or early in training camp we got to see him in person," Judge said recently. "How mentally tough he is [has been most impressive]. ... This guy never really looks fazed in anything he does. He has a quiet demeanor, but it's a serious demeanor. Once he starts talking, he'll chatter a little bit to you. But he's very focused and locked in, and it translates over to how he plays in the game."