Sawyers, who came through the youth ranks at Albion, has been in sensational form ever since rejoining the club from Brentford in the summer.
With a 92 per cent pass completion rate, the 28-year-old has been instrumental in helping Bilic implement his possession-based game at The Hawthorns.
But while the head coach is thrilled with his midfielder, he warned he will always push him to be better.
“He’s a top player,” Bilic said when asked about Sawyers. “The way he passes the ball, the way he kills the opponent, the way he dictates the game.
“He’s a brilliant player and that’s why we wanted him to come home and play for us – we did everything we could to bring him in from Brentford.
“He’s different class and one of the biggest reasons why we’re playing so good.
“But he can do much better. I’m never going to be happy with him.”
Despite Bilic’s tough love approach, Sawyers says the trust he receives from the head coach has been key to his impressive form this season.
And the midfielder, who describes himself as a ‘Marmite-type’ player has also thanked Albion fans for accepting him.
“The fans have really taken me on board and that’s a massive thing for me personally as I’m a Marmite-type player,” he said. “Sometimes I’m described as lazy or too laid back or casual, but I’ve not had that here.
“That’s given me that extra two per cent that’s made me think they’re on board with the kind of player I am. That’s the kind of support I need as a player.
“In the dressing room I’ve definitely got it (support), from the manager I’ve definitely got it, but to have it from the 12th man as well makes a whole lot of difference.”
Sawyers says he is also drawing confidence from his team-mates.
“The dressing room is very much an easy dressing room and I feel like I’ve got the trust from them,” he added.
“That gives me the platform to play confidently. There are times when I’ve lost the ball and it’s not like someone will rip my head off. That makes things easier.”
Meanwhile, West Ham boss Manuel Pellegrini has given Albion a boost by saying he wants Grady Diangana to remain at The Hawthorns for the entire season.
The winger’s performances had led to suggestions he could be recalled from his loan in January.
“I think that Grady is doing what we wanted for him,” Pellegrini said.
“He’s a player without any doubt will be part of West Ham in the future. I trust a lot in Grady and I think it was better for him to go and play 40 games this season and be ready for next season, than to play here just some games.
“I think he must finish his season where he is.”
Despite Pellegrini’s words, Albion fans won’t get too excited with former Leicester boss Claude Puel saying something similar before recalling Harvey Barnes last season.
“He (Barnes) is a young player, he is in a good place, he can continue to improve,” Puel said on Barnes last October.
“We don’t know what can happen in the transfer window but my priority is for him to remain.”