They've seen it on every locker room wall:

"When the going gets tough, the tough get going."

But the message never sunk in for 17 seniors on the Harvard football team. When the going got tough--when The Crimson disclosed seniors had signed a letter criticizing the coaching reign of Joe Restic--these big, tough football players turned into towards.

In a letter to The Crimson published Monday, they attacked John F. Baughman's story as "irresponsible and insensitive journalism" that was "not based on solid, hard core fact."

Every word in Baughman's story was true, and the players knew it.

That the players backed down is ironic, because they had just taken a courageous step--one that many players on many Restic teams have wanted to take for a long time. They said that they were not happy with the way Restic coached: they said there were problems with the Harvard football program.

And it is important to know--as all these seniors do--that the original letter about Restic was not the action of a few grumblers but the consensus of nearly every senior on the team.

Joe Restic seems to think otherwise. He told the Boston Globe Saturday. "What hurts is that those few who had problems didn't have the courtesy to come to my office to discuss it instead of going first to The Crimson Those people didn't want anything solved I have a pretty good idea who the few are, and they're trying to capitalize on this."

Running backs Jim Acheson. Steve Branucci and Jim Callinan, the three who have walked the petition around to the players since December, have taken most of the heat. But they are not the ringleaders, they are the messengers--delivering the feelings of virtually all the seniors.

The letter is not, players say, a personal vendetta against Restic. It was not written with the intention of getting Restic fired. It was written to air out important grievances that many players have with Restic's coaching.

The letter, which has been described by several players who signed it, deals with three major areas.

*that Restic was inaccessible and uninspiring.

*that Restic's offensive system--the Multiflex--was too complicated and not effective for Harvard teams.

*that Restic blamed the players--and not the Multiflex--for Harvard's offensive fastures.

Each complaint has a history. Restic, whose teams have accumulated a 59-39-2 record in 11 years has long ascribed has teams' failures to his personnel and not his system. After the 14-0 loss to Yale in 1980--the first of two straight shut-out losses to Yale. Restic's teams have experienced--he told this reporter that "The Multiflex was more effective in this game than in any game this year We just couldn't execute."