Lee Bowyer is determined for Naby Sarr to show more aggression and “spitefulness” as he fights for a place in Charlton Athletic’s starting 11.

The 24-year-old finished past Hugo Keto as the Addicks held Brighton and Hove Albion to a 1-1 draw in a pre-season friendly at the Valley.

While the defender impressed against Premier League opposition, he is being urged to adopt a nastier mentality in defence.

Bowyer said: “He’s a machine, isn’t he? Would I like to have played against him? No. But he needs to be more aggressive. He has to, he’s a centre half. It’s a physical game. But, does he have all the attributes? Yes.

“We’ve just got to try and get this spitefulness out of him, you know, and just make him more aggressive.

“You see him in the keep-ball sessions that we do, he’s one of the best in the keep-ball. His feet are unreal. For the size of him, his feet are unreal.

“He has got all the potential and all the attributes, we’ve just got to try and get it out.”

Meanwhile, Bowyer is remaining coy over new signings before the transfer window shuts as Charlton prepare for their opening day clash with Sunderland.

The Addicks boss didn't rule out further additions but underlined the importance of those coming in having to improve what is already at the club.

He added: "We know what we need but we’re not going to rush it because there’s no point bringing in anybody that’s not going to make us better. [Darren] Pratley has made us better, Lyle Taylor has made us better.

"I think it would be silly for me to bring in people that are not going to improve us and, to be fair, there aren’t many out there and not that we’re after anyway.

"We don’t have a massive budget but we’re working at it and hopefully we’ll bringing in a few more [signings]."