Central defender Ferdinand played an hour and American midfielder Williams managed 45 minutes in the fixture with Brighton & Hove Albion's youngsters on Monday.
Ferdinand has been struggling with a hamstring problem, while Williams has not played since April and is "itching" to get back on the pitch after the frustration of missing the World Cup because of a knee injury.
"I'm positive and ready," Williams told BBC Radio Berkshire. "I'm itching. Everyone that knows me knows I love football, I love to be on the pitch when the fans are screaming and shouting, it gives me an extra 10 or 20%.
"I love being on the pitch, fighting for my teammates, the whole club and I feel like a new signing.
"It's been a frustrating three months and it was more frustrating when I heard the news I had to have surgery because I missed the World Cup. I've left that behind me now, I'm looking forward to helping the team; we still have a lot of games and I want to help the team get in the playoffs."