The former Middlesbrough schemer started his first game for almost two years in Tuesday's 3-0 Carabao Cup victory over Crewe Alexandra in front of just over 34,000 at Elland Road, paying for just over an hour.
Sidelined with a long-term hip injury, the 29-year-old's previous competitive game was against Charlton on September 28, 2019.
Bielsa said: "Forshaw is very well prepared. He sacrificed a lot in these last two months.
"Progressively, if he keeps healthy and he acquires the competition rhythm, he has all the virtues to be a player that can shine.
"He was going to play between 45 minutes and an hour. And he could handle the rhythm of the game, so we're satisfied."
Three late goals saw United overcome the resistance of a plucky Crewe side on an evening when Bielsa elected to field a strong line-up.
Kalvin Phillips, who opened the scoring for Leeds 11 minutes from time and captained his hometown side, opened the scoring on a night when Diego Llorente made his first team return.
The likes of two-goal Jack Harrison, Tyler Roberts, Helder Costa and Rodrigo also started, alongside first-choice keeper Illan Meslier, Jamie Shackleton, Junior Firpo and Pascal Struijk.
Bielsa continued: "Shackleton is a player that deserves to play and Llorente is coming back from injury. Junior needs the minutes and Phillips had played less than the rest.
"Rodrigo didn't play the last game. Helder, like Shackleton had had few minutes. Harrison when he puts games together, it improves him. Forshaw hadn't played an official game for a long time. For each case there was a motive.
"Every player that played did so justifying why. Some because they had played less in the pre-season, some others were coming back from injury.
"Some because they had the level of a starter, but they have less minutes. And some of them because they can play more than once a week. That's to say we pick the players with each case in mind."
Nothing in particular. He had the option to play in an important competition like the Championship and like the club thought, I thought it was a good opportunity for him."