Brendan Rodgers remains determined to sign a left winger before the transfer deadline to allow Philippe Coutinho to develop as a No10 at Liverpool.

The Liverpool manager was left frustrated by the refusal of Fenway Sports Group, the club's owners, to pursue a deal for Willian once Anzhi Makhachkala received an increased offer from Tottenham Hotspur earlier this week. Willian is the third major transfer target that Liverpool have missed this summer, following Henrikh Mkhitaryan and Diego Costa, and with Stewart Downing sold to West Ham United Rodgers wants another attacking option in before 2 September.

Rodgers's reasoning is partly explained by the outstanding form of Coutinho. The Brazilian has been deployed mostly on the left since his £8.5m arrival from Internazionale in January but his manager believes the 21-year-old can make a bigger impact in the centre.

"His ideal position is in the No10 role," said Rodgers, who is also in the market for an experienced central defender. "I've seen him play when Inter had two advanced players and one holding, and he was one of the advanced players. Whether it's a two or a one, he can play in that role, or from the side. But centrally, that's where I see him playing. That's why I'm looking to sign someone for the left wing."

Coutinho's start to his Liverpool career is in marked contrast to a difficult 30 months in Italy, where he struggled with injury and spent six months on loan at Espanyol. But Rodgers insisted: "I don't think he was a failure at Inter. At the time, Inter needed to move players out to get money. He was one of the players, like [Wesley] Sneijder, they had to move on. In his time when he was fit, he actually performed well. But he was a young player. Notoriously in Italy, a lot of young players don't get the opportunity, hence the reason he went to Espanyol on loan.

"He was only 18, 19 when he started at Inter. You don't see many young players playing in Italian football. He was at the stage where his quality demanded he played regularly, and it was about finding a stage for him to do that. When I was aware he was available having known of him when he was in Brazil, I thought it would be perfect for us. He's a wonderful player, a joy to watch. He's just turned 21 and he has a great career ahead of him."

Arguably the only reservation over Coutinho since he joined Liverpool is his impact against the leading teams in the Premier League. He was substituted early against Chelsea and Tottenham last season but Rodgers believes there were mitigating circumstances in both fixtures.

"He was still gaining his fitness and those were high-tempo games," the manager explained. "But I have no doubts about him on the big stage. I've seen him play in Champions League games for Inter, he can play in the big games, he has the temperament and quality. He might not have been at his best in those games last season but he has contributed."