Lokonga cut ties with Arsenal this summer, signing for Hamburg after spending last season on-loan with Sevilla.
His brother M'Poku, now with Al-Batin in Saudi Arabia, is a former Tottenham youth teamer and told Voo Sport: "When you look at his performances at Luton Town, Crystal Palace or even Sevilla, he plays like a boss.
"It's just that he's scored fewer goals. Here at Hamburg, he's scored two goals. But his performances haven't necessarily changed compared to when he was at Arsenal. When you look at his early days at Arsenal, he played some magnificent matches. He plays big games.
"It's just that at a certain point, Mikel Arteta… That's where I sometimes get angry with certain coaches. He wasn't 100 per cent fair to him.
"Otherwise, when you look at his performances everywhere he's been, he's been successful. But when you score, it makes more noise."