Cresswell, 19, son of ex-Leeds, Sheffield United and Sheffield Wednesday forward Richard, 18, lined up for just his second senior start for United in the game at Craven Cottage.
His only other start came in a tie in the same competition last season, against Hull City.
On the progression of Cresswell, an unused substitute in United’s last four Premier League games and his readiness for a potential top-flight debut, Bielsa said: “I wouldn’t have any inconveniences.
“The performance from the other day was not a definitive performance, but I have no argument to say that he took advantage of the opportunity he was given and he deserved it.
“He observed in the game against Newcastle after we took Ayling off. I pushed (Jamie) Shackleton in as a defensive midfielder and put (Kalvin) Phillips into the back line in place of Cresswell coming on for Ayling, which would have been more natural.
“That indicates a position of mind in respect to Cresswell. After the game against Fulham, taken a significant step forward and I have to read that message.”
Meanwhile, Bielsa says that Leeds will again be without, Diego Llorente, Robin Koch and Patrick Bamford for Saturday’s home game with West Ham, while Raphinha and Luke Ayling will continue to be monitored.
Covid protocols will mean that Jack Harrison could be available, although his level of fitness - after training at home - will be assessed.
Bielsa said: “Llorente, Koch and Bamford won't be available.
"The rest of them, I couldn't tell you either way.
"Don't think I'm holding back information. Players are subject to the evolution of whether it will allow them to play. If i said whether they definitely were or were not going to play then I would not be certain. So I cannot confirm either alternative.”