Teams have a good indication whether new veteran acquisitions, either by trade or signed as free agents, are paying the expected dividends, by the middle of the season. Not all of the high-priced moves, or players acquired for significant draft capital, pan out. On the flipside side, there are always some low-cost additions that turn out to be pleasant surprises.

Ten veteran newcomers making a difference have been identified at the halfway mark of the 2021 season. Contributions and salary were taken into account when making the selections.

Matthew Stafford, QB, Rams

Stafford has been everything Rams head coach Sean McVay thought he would be when the Lions accommodated his request to be traded to a contending team after he soured on Jared Goff last season. Goff was included in this trade where the Lions received a 2022 first-round pick, a 2023 first-round pick and a 2021 third-round pick from the Rams.

Stafford was viewed as the missing piece when acquired for a Rams team that had the NFL's best defense in 2020. The Rams were eliminated in the divisional round by the Packers last season after beating the Seahawks in the wild card round.

Stafford is having the best season of his 13-year NFL career. He is leading the NFL in passing yards (2,771), passer rating (111) and is second in touchdown passes (23). None of this will matter for the 7-2 Rams if Stafford, who has never won a playoff game, can't end his postseason drought.

Stafford will be in a contract year in 2022. It's conceivable he could become the league's highest-paid player -- Chiefs quarterback Patrick Mahomes, at $45 million per year, currently holds that title -- before the start of next season even if the Rams' quest for a championship falls short. The five-year, $135 million contract extension Stafford signed in 2017 put him at the top of the NFL's pay scale despite a lack of postseason success.

Matt Judon, EDGE, Patriots

Judon has been the crown jewel of New England's spending spree in free agency. He signed a four-year, $54 million contract (worth up to $56 million through incentives) with $32 million of guarantees after being designated as a franchise player by the Ravens in 2020. Judon is on the verge of becoming the first Patriot with double-digit sacks since Chandler Jones' 12.5 in 2015. His nine sacks are tied for third-most in the NFL in 2021. Judon's 44 quarterback pressures (combined sacks, quarterback hurries and quarterback hits) are fourth in the NFL, according to Pro Football Focus.

Trey Hendrickson, EDGE, Bengals

Hendrickson came out of nowhere last season to tie three-time NFL Defensive Player of the Year Aaron Donald for second in the NFL with 13.5 sacks. In his three previous NFL seasons, Hendrickson had a total of 6.5 sacks. This made Hendrickson a classic buyer-beware free agent because of his limited track record performing at a high level when the Bengals gave him a three-year, $45 million contract. Hendrickson is proving his 2020 season wasn't a fluke. He is tied for sixth in the NFL with 8.5 sacks. Per PFF, Hendrickson's 42 quarterback pressures are tied for sixth-most in the league.

De'Vondre Campbell, LB, Packers

Campbell didn't sign a one-year, $2 million deal with an additional $500,000 in playing-time incentives until June because of a tepid free agent market. He is thriving in Green Bay as an every-down linebacker. Campbell has been on the field for 97.6% of Green Bay's defensive plays (559 of 573 snaps). He was named NFC Defensive Player of the Month for October. In five October games, all victories, Campbell had 45 tackles, one sack, three tackles for loss, an interception, two forced fumbles and two passes defended.

Cordarrelle Patterson, RB/WR, Falcons

Nobody envisioned Patterson becoming Atlanta's most consistent offensive weapon when he signed a one-year, $3 million deal with $1.7 million fully guaranteed in April. Patterson leads the Falcons with 278 rushing yards and 38 receptions. Patterson's versatility has been on fully display as 145 of his 254 offensive snaps have been in the backfield at running back while 108 have been at wide receiver, according to PFF.

Patterson has already set a new career high with 737 yards from scrimmage (combined rushing and receiving yards) this season, which is 15th in the NFL. A member of the 2010s All-Decade team as a kick returner, Patterson's 1,064 all-purpose yards (combined rushing, receiving and return yards) are third-most in the league.

Casey Hayward, CB, Raiders

Hayward has bounced back from the subpar 2020 season that led to the Chargers releasing him. 

He signed a one-year, $2.5 million contract (worth a maximum of $4 million through incentives) in early May to continue playing for Raiders defensive coordinator Gus Bradley, who held the same position with the Chargers from 2017-20. Opposing quarterbacks are completing 47.8% of passes (11 of 23 attempts) when targeting Hayward for a 64.0 passer rating this season, according to PFF metrics. Hayward hasn't given up a touchdown in coverage, either.

Haason Reddick, EDGE, Panthers

Riches in free agency didn't await Reddick despite tying for fourth in the NFL with 12.5 sacks last season. Consequently, Reddick took a one-year, $6 million deal worth up to $8 million through incentives from Carolina. He has reunited with Matt Rhule, his college head coach at Temple. Reddick is tied for sixth in the NFL with 8.5 sacks.

Corey Linsley, C, Chargers

Linsley, who earned All-Pro honors in 2020, was given a five-year, $62.5 million contract with $26 million in guarantees to help stabilize and anchor the Chargers' offensive line. The deal briefly made Linsley the NFL's highest-paid center. Linsley hasn't allowed any sacks or quarterback hits this season.

Teddy Bridgewater, QB, Broncos

Bridgewater became expendable when the Panthers traded a 2021 sixth-round pick, a 2022 second-round pick and a 2022 fourth-round pick to the Jets for Sam Darnold in April. He was promptly traded to the Broncos for a 2021 sixth-round pick to compete with 2019 second-round pick Drew Lock for the starting role in Denver. To facilitate the trade, Bridgewater took a pay cut from $18 million to $11.5 million, of which $7,062,500 is being paid by the Panthers, and his 2022 contract year was deleted.

Bridgewater has been steady in helping Denver get above .500 through nine games for the first time in five years. The five wins match Denver's win total from last season. Bridgewater is completing 70.2% of his passes (third in the NFL) and has a 101.3 passer rating (ninth in the NFL), both career bests. He also has 14 touchdown passes against five interceptions.

Bridgewater isn't viewed by most to be the long-term answer for the Broncos at quarterback. Reigning NFL MVP Aaron Rodgers had his sights set on playing in Denver during his offseason rift with the Packers. Denver was also reportedly an acceptable trade destination to disgruntled Texans quarterback Deshaun Watson over the offseason.

Emmanuel Sanders, WR, Bills

Sanders didn't waste any time in finding a new home after the Saints released him in March because of the league's most challenging salary cap situation. He signed a one-year, $6 million deal with an additional $500,000 in incentives where $5.9 million was fully guaranteed. The 34-year-old is averaging a career-high 17.1 yards per catch, which is fifth in the NFL, on 28 receptions. He is also on pace for his first 1,000-yard receiving season since 2016.