Bamford ended speculation linking him to a possible move to Tottenham on Thursday by signing a new five-year contract at Elland Road.
The 27-year-old, whose previous four-year contract was due to expire next summer, had been a reported target for Spurs amid uncertainty surrounding the future of England skipper Harry Kane.
Bielsa, speaking hours before Leeds announced that Bamford had signed up for the club until 2026, said: “Bamford is a very important player for us and one of the best strikers in English football. “
Bamford was the second most scoring Englishman in the Premier League last season with 17 goals, behind Kane, who scored 23.
Leeds will look to kick off their new campaign with a home win over Rafael Benitez’s Everton on Saturday.
White fans’ expectations after ninth place last season were dampened by their 5-1 defeat on Matchday 1 at Manchester United.
Bielsa, generally, has said he takes full responsibility for how his team were defeated.
“The manager is not good if he tells you what’s going to happen in the game,” he said.
“It’s not good either because it uses resources to incorporate knowledge so that the things you don’t want happen.
“It’s only good if the process of avoiding what hurts a team is effective, which is why I explained to the players that I feel absolutely responsible for the situations that arose in the game against Man United. “
The Argentine said his biggest disappointment with his team’s defeat at Old Trafford was letting the fans down.
“We feel the expectations and the hopes that the fans had for this game, we feel we have cheated them and if there is something that really hurts, it is to disappoint, not to give what you want. ‘we are expected,’ he said. .
Kalvin Phillips was an unused replacement last Sunday after Bielsa felt he was not fully aware of his exploits in England at Euro 2020.
But the Leeds talisman could return against Everton, who gave Benitez a dream start as manager by beating Southampton 3-1 at Goodison Park on Matchday 1.