Wilkinson, whose drop-goal secured victory against Australia in the final of the 2003 World Cup, brought the curtain down on his England career last December having won 91 caps for his country.
The 33-year-old is playing club rugby with French side Toulon, though, and Gatland has not ruled out the possibility of the fly-half being a part of the Lions tour to Australia if his performances merit it and he is available.
Asked if he might consider including Wilkinson as a possible kicking coach, Gatland was quoted as saying by several Sunday newspapers: "I might well think about it but he may also be available as a player. He's still a fine a player and only 33. That's not old.
"For me, everyone is in contention. The slate is clean for every player who wants to be considered.
"No one is ruled out or pencilled in and if you are playing well enough then whoever it is - whether it is Jonny Wilkinson or whoever, it's all about how players are performing for their clubs or countries.
"We've selected players who have been playing well just for their club sides and have done well for the Lions.
"They don't have to be playing for their countries.
"What is important if they are not playing international rugby is that they have to be coming from a side that is performing particularly well."
Wilkinson has made six Test appearances for the Lions, earning his caps in 2001 and 2005.
- Jonny Wilkinson