But the giant front row has made good progress this week and could now force his way back into team selection for the trip to Reading on Saturday.
"We have had some good news with Tevita Taumoepeau and it looks like he should be okay for the weekend," said Ruddock.
"He has had a cold on his chest which has stopped him training today, but his calf seems to have settled down a little bit better than we thought and we think he will be fine.
"Callum Black will be out for three weeks and he joins people like Shaun Ruwers and Matt Mullan on the sidelines.
"But Olivier Sourgens trained today with Adam Black, we also have people like Jack Gilding who has had first team action.
"I will carry on looking around in case I do need to bring someone in, but at the moment I'm sure that we are going to be okay for this weekend.
"There are a lot of flu bugs and colds around at the moment, you don't know what is around the corner in terms of that, but we are not expecting any more major problems before the weekend."
Grove has today (Wednesday) returned to training with Warriors after his exploits with Scotland that saw him play all three international games with Fiji, Australian and Argentina.
"Alex has had three big physical tests with Scotland, the highlight of which was the victory over Australia," added Ruddock.
"He is a bit sore and bruised, but he will drop into training later in the week and potentially he could be in our panel this weekend against London Irish."