The Six Nations had looked an unlikely aim for Croft, who suffered a triple fracture to his neck a year ago but his return to first-team action with Leicester means he could play some role in England's push for a grand slam.
"The indications last week were that it might be a bit early for Tom to get involved in this Six Nations," England head coach Stuart Lancaster said in an RFU statement.
"But having played back to back games he has now had the all clear from the specialist and Leicester's and our medics.
"I also had a good chat with (Leicester coach) Richard Cockerill. He is happy with his form and we can clearly see he is playing well, but most importantly Tom feels he is ready - it is great to have him back in."
Croft made his fifth start for Leicester since returning in January last weekend, impressing in the thrashing of Sale, and while England do have plenty of options in the back row, the experienced Croft's return is a boost.
"We have competition in all places but the back row is very competitive and to have Tom available just adds to that so we are looking forward to seeing how he does this week," Lancaster said.
The 27-year-old has won 36 caps for England since making his debut in 2008.
Owen Farrell is set to miss the penultimate match of the championship at Twickenham, however, having lost his battle with the thigh strain sustained against France, so Toby Flood will start against Italy.
"Owen's still got the quad injury which I want to make sure has settled down completely. It's fair to say that you can read into that that Toby Flood will be starting," Lancaster said.
England are on course for a clean sweep in the Six Nations after wins against Scotland, Ireland and France. They face Italy on Sunday and conclude against Wales in Cardiff on March 16.