When asked by British & Irish Lions broadcast partners TalkSport if Warren Gatland's men could win the series 3-0, Lynagh said: "I think so, yes. Australian teams in the Super 15 tournament have had quite a few injuries to key players.
"People like Scott Higginbotham, Digby Ioane and a number of other players who would have appeared in the Test series.
"That's hurt Australia and their problem is that they don't have a huge amount of depth. They have 20-odd players who are strong but, as soon as you scratch the surface, they become a bit thin.
"Having seen the Lions perform in Hong Kong, albeit against a weaker opposition, they are a very strong squad with lots of seasoned players. They are physically big and, even as an Australian, I'm starting to get a little bit worried about the Test series coming up."
Lynagh, who was part of the Wallabies side that crashed to a 2-1 series defeat in 1989 has also played down the notion that the Lions will be under prepared for the Test matches.
"We talk about how hard it is for the Lions to come together with all the different nations and the fact they have to gel quickly," added the World Cup winning fly-half.
"The Lions have six games to lead up to the first Test, so they have enough time to get together, Australia have no warm-up matches.
"Yes, they might have played together before but sometimes people are injured and that sometimes means that they won't have played together. So, despite the Lions saying that it's difficult, they will be better prepared than Australia."