AFL injury ladder: How hard your club has been hit?
Richmond has been hit hard by injury but when it comes to the number of games lost by best 22 players because of injury, there are three clubs worse off than the Tigers and a premiership contender has been hit just as hard. See the injury ladder.
Five of Richmond's six best players and eight of their top 13 from last year's Jack Dyer Medal will miss the clash with the Crows.
Edwards has been ruled out with hamstring tendinitis, with the Tigers adamant Cotchin's third hamstring episode of the season is only soreness rather than another tear.
The Tigers' injury plight could eventually influence a risky recall for Alex Rance during finals given their fading premiership hopes.
Of their eight Tigers in the All-Australian squad of 40 last year, Jack Riewoldt, Rance, Kane Lambert, Edwards and Cotchin will miss and Josh Caddy is badly out of form.
Richmond will have to hang tough and hope it can burst up the ladder in a seven-match stretch of games to finish the home-and-away season.
In that stretch they take on contenders West Coast, Brisbane, Collingwood, Port Adelaide and GWS as well as Melbourne and Carlton.
Richmond football boss Neil Balme said the injury was only minor but given Cotchin has twice injured the hamstring this year he had decided against risking it.
"He's not going to play, he's sore. It puts a bit more pressure on, but that's all right," he said.
"He's just a bit sore in the hamstring, but it's not the same. I reckon if he hadn't have had the problem before, he would have played.
"The fact we're playing on the Thursday makes it more difficult. If we'd played on Saturday or Sunday (he was a chance), but we won't take the risk."
A club whose leaders had seemed bulletproof has lost the fourth-most games from injury to its best 22 this year.
Remarkably, by Friday only four of its players will have taken the field in all 13 games this year - Tom Lynch, Jack Higgins, Kamdyn McIntosh and Dion Prestia.
Edwards had played every game until pulling up sore this week.
The Tigers will have to make a tough call on Rance, hoping to recover from an ACL rupture in 26 weeks to play in a qualifying or elimination final.
Coach Damien Hardwick is adamant the club will consider his claims as he steps up his recovery that has already shown incredible signs in its early stages.
Hardwick said on Friday night he was hoping Jack Riewoldt would be back in Round 16, with David Astbury likely back after next week's bye.
Kane Lambert (Achilles) and Toby Nankervis (groin) are still some weeks away from returning.
Brisbane and Fremantle have had 14 players take part in every game this year, with St Kilda (13), Collingwood and the Western Bulldogs (both 12) not far behind.
Incredibly, Brisbane has lost just 10 games to injury from its best 22 this year, clearly the best run ahead of the Dogs (39) and Hawthorn (41).
Melbourne has lost 100 games to injury from players in its best 22, with GWS second (72 games) in front of St Kilda (68) and Richmond (67).
NUMBER OF GAMES LOST TO INJURY FROM BEST 22
1 Melbourne 100
2 GWS Giants 72
3 St Kilda 68
4 Richmond 67
5 Collingwood 66
5 Sydney 66
7 Carlton 64
8 Gold Coast 61
9 North Melbourne 60
10 Geelong 57
10 Fremantle 57
12 Port Adelaide 53
13 Essendon 47
14 West Coast 45
15 Adelaide 43
16 Hawthorn 41
17 Western Bulldogs 39
18 Brisbane Lions 10
NUMBER OF PLAYERS WHO HAVE PLAYED EVERY GAME
Brisbane Lions 14
St Kilda 13
Western Bulldogs 12
GWS Giants 11
West Coast 9
Port Adelaide 9
North Melbourne 9
Gold Coast 9