Itoje last week suffered a setback in his recovery from the knee ligament damage sustained against Ireland on the opening weekend of the tournament and has been omitted from a 31-man training squad named for the final-round fixture at Twickenham.
"Maro's a class player, but his health comes first and that's the most important thing," said defence coach John Mitchell, who was unable to provide a date for his return.
Head coach Eddie Jones was non-committal when asked about Itoje after Saturday's 57-14 rout of Italy, declaring "we'll just wait and see", but the second row's championship is now definitely over with only 53 minutes played.
It was hoped that he would return to face Italy, only to injure the same right knee that was hurt in Dublin during a forwards drill at the squad's training base.
While the loss of Itoje is a blow for England, who can still win the Six Nations if results go their way, they can at least take heart from the performance of George Kruis at Twickenham on Saturday.
Jones singled out Kruis as his man of the match on the grounds of his workrate and the 29-year-old is set to continue his second row partnership with Joe Launchbury against the Scots.
Harlequins flyhalf Marcus Smith, 20, has been called into the training squad for the first time in this Six Nations in a snub to Danny Cipriani, who does not appear to be in Jones's World Cup plans.
Mitchell confirmed that Jack Nowell is available for selection after recovering from a shoulder injury sustained against Wales on February 23, confronting Jones with a selection dilemma on the right wing.
Fijian-born 21-year-old Joe Cokanasiga was outstanding in Nowell's absence as he celebrated his fourth cap with a man-of-the-match display that former England coach Clive Woodward said evoked memories of New Zealand superstar Jonah Lomu.
Jones has dismissed the comparison as "ridiculous" and Mitchell sounded an equally cautious note.
"We've got to be very careful comparing people. Joe is Joe and he will cut his own path," Mitchell said.
"He's very young in terms of his international experience so it's important that we focus on improving him and making sure we can keep his feet on the ground.
"Joe is getting better with each outing. He'll continue to improve and we'll focus on his basics."
England are second in the Six Nations table, one point behind Wales, who face Ireland in Cardiff on Saturday searching for their first Grand Slam since 2012.
Forwards: Dan Cole, Luke Cowan-Dickie, Tom Curry, Ben Earl, Charlie Ewels, Ellis Genge, Jamie George, Nathan Hughes, George Kruis, Joe Launchbury, Ben Moon, Brad Shields, Kyle Sinckler, Elliott Stooke, Billy Vunipola, Harry Williams, Mark Wilson
Backs: Joe Cokanasiga, Elliot Daly, Owen Farrell (capt), George Ford, Jonathan Joseph, Jonny May, Jack Nowell, Dan Robson, Henry Slade, Marcus Smith, Ollie Thorley, Ben Te'o, Manu Tuilagi, Ben Youngs