Eddie Jones is refusing to rule out including Maro Itoje in England's squad for the Six Nations opener against Scotland, but says the Saracens star needs time to develop in international rugby.
Second-rower Itoje gave a timely reminder of his blossoming talent with a man-of-the-match performance in Saracens' 19-13 victory over Sale Sharks at Allianz Park on Saturday, with England coach Jones an interested onlooker.
The 21-year-old was one of 10 players cut from a 33-man training squad for the Six Nations opener at Murrayfield, but may be called upon if Courtney Lawes fails to recover from a hamstring injury in time.
Jones says Itoje is in this thoughts, but needs to work on his game to make the step up to the highest level.
"Courtney is progressing. We'll give him until Thursday. It looks pretty positive. He probably won't train until Thursday, but we're hopeful he'll be all right," Jones told England rugby's official website.
"I went to Saracens - I hid in the stands - and it was the best game I've seen Itoje play for them. It was really good, very impressive.
"It's never too late to get in the 23. The 23 isn't set in stone, but generally speaking the 23 that we kept are the front-runners. Now they can play themselves out of selection by injury and by attitude, so there are still opportunities.
"But remember that my job is to make Test rugby players. There's a step from club rugby to Test rugby here, as there is in every country. There are subtle but strong differences between a good club player and a good Test player.
"I want Maro to be a 60-Test player. I don't want him to be a 10 or 20-Test player. Sixty-Test players start their career well and build on that.
"Some players you can expose too late, some too early. My gut feeling on Maro is that he's definitely progressing, but he needs just a little more time.
"And if he's going to play 60 Tests for England we can wait because that would mean he's a bloody good player and that's what I think he will be."