WASHINGTON – In a best-case scenario, Royce Lewis might be only a couple of weeks away from rejoining the Twins lineup.

Lewis ran the bases Monday at Target Field. He's already doing all other baseball activities — taking ground balls, hitting on the field and hitting in the batting cages — so this is the last hurdle he needs to clear before he begins a rehabilitation assignment.

Head trainer Nick Paparesta said Lewis will continue running the bases throughout the week, and they will simulate game-like scenarios Friday.

"We're getting close to a point with him, I think, where we start heading in the right direction of a rehab assignment," Paparesta said, "but we're not ready to say yet when."

Lewis, sidelined since Opening Day because of a partially torn quad in his right leg, passed all his running tests last week when he worked on changing directions and ramping up his sprints to nearly full speed.

"We just have to see how he does on the bases," Paparesta said. "Friday will be a big tell for us because we're going to do a lot of stuff with him where we're going to try to put in as many game-scenario situations as we can."

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Lewis has admitted his frustration during the rehab process because of the lack of a firm timeline, and he says his quad feels good.

"We have to go by the science a little bit on that and explain that to him," Paparesta said. "You just take the time to explain to him every time what we're doing, why we're doing it, and just make sure that his group of people around him understand that as well. I think ultimately you just get to a relationship where Royce comes in every day, tells us he's good, and we're excited to hear that, and that's good, but he knows there are things that we need [to do]. I think it's just a good give and take a little bit on that side of things."