The Exiles prop was selected to start the Aviva Premiership clash at Gloucester, but he was a late withdrawal because of persistent knee trouble. England kick off their RBS 6 Nations campaign in four weeks' time, and there must be considerable doubt about Corbisiero's prospects.
"It is very frustrating for us, it is very frustrating for 'Corbs'. It is a tough time for him, and it is a difficult one to balance," Smith said, following his team's 18-12 Kingsholm success. "His knee is a mess. He has played one-and-a-half games for us this season, and it is very disappointing."
He added: "Sitting here right now, I couldn't tell you if he is going to play next week or not. He has got degenerative knee issues.
"He trained twice this week. We are bringing him back, and then at the captain's run he pulled out prior to it, and we had to make a change.
"There is not much of a decision to make when a bloke's knee has blown up and he feels he can't play. You can't put a gun to his head and tell him to get on the paddock.
"He is an honest person, he is a good bloke. He desperately wants to play for us, but it is a very frustrating situation."
Gloucester rugby director Nigel Davies had few complaints after his team suffered a first home defeat since September 1.
"We are hugely disappointed," Davies said. "For whatever reason, as a group, we got it wrong today. We don't think that is acceptable.
"The important thing is that when you lose games, it's how you deal with it, manage it and come back. Today showed we are not good enough to slip off the hard work, intensity and accuracy. When we do that, like we we did today, then we were second best."