Joe Launchbury has declared himself "ready to go" as he handed England coach Eddie Jones a timely fitness boost.
Jones initially stated that Launchbury was a doubt for the start of the Six Nations, but the Wasps captain has timed his return well with two rounds of European action preparing him to face Wales.
"The rehab has gone really well. As soon as I did it I was always really hopeful for this weekend," Launchbury said.
"I'm delighted how it's gone and how the calf feels, so I'm ready to go again."
Launchbury's availability has grown in significance after Chris Robshaw underwent shoulder surgery, a development that means Maro Itoje is likely to move at blindside flanker, with either Launchbury or Courtney Lawes partnering George Kruis at lock.
Launchbury is backing Itoje to prove a success if asked to make his first Test start in the back row, but insists Robshaw is a major loss to the team.
"Maro is talented enough and has the athleticism to play six, but there's a whole host of players who can certainly play there," he said.
"Eddie has spoken about Chris and his value to the team, but as players we have known his value for an extremely long time.
"He's always the guy who is making a cover tackle in the corner or going the extra yard.
"He'll be a massive loss for us, but whoever comes in - just like in November when there were some injuries -- I'm sure it'll be fine."