Mohamed Salah was affected by his contract saga in the latter stages of last season, according to Liverpool team-mate Virgil van Dijk.
Egypt international Salah signed a new deal at Anfield last month worth a reported £350,000 a week, making him the highest-earning player in the club's history.
That brought an end to months of speculation regarding the 30-year-old's future, having himself hinted that he may move away as he entered the final year of his previous deal.
Despite Salah finishing last season as the Premier League's joint-top goalscorer alongside Son Heung-min, Van Dijk believes the contract standoff took its toll on the Egypt star.
"At the end of the season, from maybe April until the end, there was a lot of talk about his contract and stuff," Van Dijk told The Telegraph.
"We're all human beings and maybe that affected him a little bit, unfortunately."
The 118 Premier League goals Salah has scored since his first Liverpool campaign in 2017-18 is 13 more than next-best Harry Kane.
Former Chelsea forward Salah scored 27 goals in his first 31 appearances for the Reds in all competitions last season, compared to four goals in his final 20 games.
He was on the scoresheet from the penalty spot in Saturday's Community Shield win over Manchester City, and Van Dijk has backed his colleague to continue scoring regularly.
"He still showed high levels and quality and he played with a free mind and obviously he's happy to be here and I think everyone is happy to be here," the Dutchman said.
"He showed it already for the last three years. He's under the microscope all the time. He created that himself. He's such a good player and shows that consistently all the time."