Joe Staley returned to practice on a full-time basis on Wednesday. It was the first time San Francisco's star linebacker had worn shoulder pads since injuring his groin in a Week 3 loss to the Indianapolis Colts.
Willis was limited in practice last week and was a game-time scratch before the 49ers beat the Houston Texans, 34-3.
"Last week I really tried to push it to go, and it really just wasn't all the way there," Willis said from his locker on Thursday. "What I didn't want to do was lie to myself and to my teammates and not be able to give them all of me."
It turned out the 49ers didn't need Willis' services. The defense recorded four turnovers and kept the Texans out of the end zone.
Willis said he felt "amazing" at Wednesday's practice. He continues to take a day-by-day approach on his return to the field.
"I'm feeling better, still feeling it, but certainly a lot better than it was," Willis said.
Two consecutive games out of the lineup has been hard on San Francisco's play-making linebacker.
"I'm a competitor I want to be out there with my teammates, I just love this game of football," Willis said. "Any time, whether it's practice or a game, I want to compete. At the same time, too, I'm a team-player and I just want to be honest."
Willis didn't feel the need to rush back with Michael Wilhoite playing at a high level in his absence. The second-year linebacker recorded 20 tackles in his two starts, including 13 against Houston.
"Mike has played tremendously well," Willis said. "It means a lot to him. He's a guy who has always wanted to be the best he can be."
Willis has been ribbed by teammates about being away for two weeks, but he's hopeful he can return to the field to face the Arizona Cardinals this week.
"Lord's will, I'll be ready to go on Sunday," he said.