England have been told that Maro Itoje has all the attributes required to solve their crisis at openside.
Four options in a long-standing problem position have been ruled out of the entire autumn series after James Haskell, Jack Clifford, Sam Jones and Mike Williams sustained significant injuries.
The last permutation available to Eddie Jones is to deploy Itoje and Chris Robshaw as flankers either side of Billy Vunipola, thereby reprising the back row that finished June's third Test against Australia in Sydney
Jones is steadfast in his belief that Robshaw is not an openside, leaving Itoje as the player most likely to be chosen to start at seven against South Africa on November 12.
It is a role to which the 21-year-old lock and occasional blindside flanker is unaccustomed, but his Saracens director of rugby is certain he would make a success of the move.
"Maro is a very destructive player and I think he would do a great job," McCall said.
"For someone who is as tall as he is, Maro's outstanding over the ball. He gets as many turn-overs as anybody in the Premiership.
"When it's not there to get over the ball, Maro is very good at making a mess of opposition attacking breakdowns.
"He carries the ball well, he reads the game well and he's another line-out option in the back-row. It would make England's line-out pretty formidable to have a seven like that."
Itoje is happy to play in any position if it enables him to add to the seven caps he has won this year.
"I've been switching positions for a while now. It's not like asking a winger to play prop. I've played back-row, I've played second-row. It's something I'm fairly used to," Itoje said.
While England's back row resources are threadbare, they have an embarrassment of riches at lock where Itoje and George Kruis are the first choice pairing and behind them wait the formidable Joe Launchbury and Courtney Lawes.
If Itoje does change position Kruis will remain with either Launchbury or Lawes starting in tandem.
"I think what Eddie is going to look at is who are the best five back-five players he can pick for England because you've got people like Launchbury and Lawes who are playing well," McCall said.
"Maybe he has less back rows at that level and just getting his five best players on the pitch is what he's thinking.
"Time will tell with Maro because we haven't really seen him yet at openside. It's a good point that he has played so well in the second row there must be a temptation to leave him where he is."
England's mood will also be lifted by more good news with Owen Farrell poised to make his first appearance of the season in Saturday's heavyweight European collision with Toulon.
Farrell has been sidelined by a back injury but played a full role in training on Wednesday, including tackling and kicking, and if he shows no ill-effects he is set to start in the south of France.
"Owen is world-class, the best player in Europe in my opinion," McCall said.
"He's been training regularly over the last three weeks and he's a big- game player, so there are lots of things in his favour to pick him.
"In some players, match fitness can be a concern, but Owen is one of the fittest guys I have ever seen so that doesn't come into to.
"During the course of his injury he has been able to do enough in terms of his handling not to be too rusty. His personality takes over and he drives the team."