The 19-year-old has already been ruled out for the rest of the season but is likely to be sidelined for much longer.
Ramsey should have been meeting up with the Wales squad on Monday ahead of an international friendly against Sweden on Wednesday but now seems unlikely to feature in Toshack's plans for some considerable time.
Toshack said: "It is an horrific injury, it makes you want to vomit. It was a sad, unfortunate incident.
"I spoke to him this morning and he seems in decent spirits but it is a blow for the player, the club and us.
"All we can do now is hope that he has a speedy, successful recovery, but obviously it is going to be a long one.
"The information we have got is that he is as comfortable as can be expected and he seemed in surprisingly decent spirits when I spoke to him."
Ramsey's influence in both the Arsenal and Wales sides has grown in the past year.
The former Cardiff starlet has played in an advanced midfield position in Wales' most recent matches and Toshack was excited about what he might offer in the Euro 2012 qualifiers.
Wales face England as well as Switzerland, Bulgaria and Montenegro in the qualifying campaign that begins next season.
Toshack admits he will now have to formulate new plans.
"Aaron has just improved immensely over the last six or seven months," Toshack said.
"In the last couple of games we felt as though we were on the right lines for him and for this to happen, from a selfish point of view, is a big blow for us.
"But the main thing is the player at this moment in time."