Prentice Steffen, Wiggins' doctor at the Garmin team in 2009, said Wiggins' successful applications for a therapeutic use exemption [TUE] for intramuscular triamcinolone ahead of the race surprised him.
Medical records leaked by Russian hackers known as the Fancy Bears last week revealed Wiggins had used the corticosteroid to treat asthma.
"I was surprised to see that there were TUEs documented for intramuscular triamcinolone just before three major events - two Tours de France and one Giro d'Italia," said Steffen on BBC Newsnight.
"You do have to think it is kind of coincidental that a big dose of intramuscular long-acting corticosteroids would be needed at that...exact time before the most important race of the season.
"I would say certainly now, in retrospect, it doesn't look good. It doesn't look right from a health or a sporting perspective."
Retired Danish professional cyclist Michael Rasmussen, who was removed from the Tour de France and banned from cycling for doping, also told Newsnight the use of the TUEs raised suspicion.
"Just looking at the drugs and looking at the dates of the injections it looks very much like something that could have happened 10 years ago when I was riding for general classification in the Tour de France," he said.
Wiggins will discuss the issue himself in a pre-recorded interview with Andrew Marr on the BBC tomorrow.