The Arsenal midfielder will be out for at least six months after suffering a badly broken leg in a Premier League game at Stoke last weekend.
Wales are not back in competitive action until the start of the qualifiers in September but even if Ramsey is playing again by then, it is unlikely to be at first-team level.
Toshack said: "The medical people seem to think it could be six months.
"If it is, terrific, but I think we have got to plan without Aaron at the moment.
"If he does come back and we do have him it will be a bonus but we don't want to rush him, he has just got to take his time.
"He is in the right place, the people at Arsenal are pretty good.
"They have had a few of this type of injury before this one.
"For us, Arsenal and the boy himself it is one of those sad things and we have just got to get on with it really."
Playing behind the front two, 19-year-old Ramsey has become one of Wales' most influential players over the past year and scored on his last appearance against Scotland in November.
Aston Villa defender James Collins, who captained the side at the Liberty Stadium, also admitted Ramsey's loss was keenly felt.
Collins said: "Any team would miss Aaron Ramsey - he is going to be a world-class player.
"But it gives a chance for someone else to come in and stake their claim."
Further injuries to Joe Ledley and David Edwards meant a different midfield last night with Simon Davies returning after almost a year out and Blackpool's David Vaughan given a chance.
Simon Church and Ched Evans were again partnered up front in the controversial absence of Craig Bellamy.
The changes deprived Wales of a cutting edge, although the arrival of Robert Earnshaw in the second half and the dynamism of Gareth Bale almost brought them reward.
A superb goal from Bolton's Johan Elmander proved the difference between the two sides but Sweden did have several other good chances.
Ola Toivonen had a header harshly ruled out for offside and Tobias Hysen brought a fine save from substitute goalkeeper Wayne Hennessey.
Collins said: "We didn't create too many chances but every game, with these youngsters, we have got to try to take the positives out of it.
"We have got to start getting some consistency in our results and our play and unfortunately we didn't get the result.
"But every game is one for someone to get experience and I am sure the manager will say it is tough when you lose three or four to injuries.
"And I'm sure he's also had a few people [club managers] ringing up asking for players to only play 45 minutes or whatever.
"It is tough to play these friendlies but you have to try to take the positives out."
Two such positives for Collins were the performance of Bale, outstanding after the break despite an apparent knock, and his own experience as captain.
Collins said: "Every time Gareth plays he's a positive.
"He has been in great form for Tottenham and he showed it again here.
"With his pace and skill going forward he was a huge bonus.
"I'm obviously not too happy with the loss but to captain my country at any level, especially senior level, is a great honour for me."
The crowd for the low-key friendly was poor, just 8,258 turning up.
Nevertheless Collins enjoyed the Liberty Stadium experience and Wales look likely to return in the near future.
It is thought the Euro 2012 qualifiers will be split largely between Swansea and the Cardiff City Stadium, with the clash against England taken to the Millennium Stadium.
Collins said: "It is great. We played Bulgaria here and it is a great surface, a good stadium.
"The crowd was a little bit disappointing, especially after the last result - 3-0 at Cardiff.
"We might have been expecting a few more but it was a friendly in midweek."