Fassel was fired as the Giants went 4-12 and finished last in the NFC East three seasons removed from a loss to Baltimore in Super Bowl XXXV.
The Ravens ranked first in the league in rushing and last in passing this season. The Giants had the 28th-ranked rushing game and the No. 11 passing game.
"Obviously, if we can find the right parameters for Jim to join us, his credentials speak for themselves," said Billick, who was in New York over the weekend. "He's probably next to Bill Walsh, in my opinion, one of the preeminent quarterback coaches in the game. He's obviously got one of the sharpest offensive minds.
"The resource he would provide me, given his experience as a head coach, would serve a great many purposes. We've got to let this process play out and Jim needs some time to decide exactly what he needs to do."
The Giants ranked in the top half of the league in offense three times under Fassel and garnered three playoff berths.
Fassel's potential job title would be one thing to determine if he comes to Baltimore along with responsibility of play-calling and devising the game plan's direction. His addition wouldn't mean the subtraction of offensive coordinator Matt Cavanaugh or quarterbacks and receivers coach David Shaw.
Fassel could assume an advisory role, or he could fit in as an assistant head coach and quarterbacks coach to help oversee the development of Kyle Boller. Fassel has coached highly-successful passers such as John Elway, Boomer Esiason and Kerry Collins.
"I know his primary objective is to become a head coach again next year," Billick said. "He has to decide what's the best format to get that done."
If Fassel sits out next season, he would collect $2.7 million under his contract with Giants owner Wellington Mara. If he joins the Ravens, New York would be responsible for that amount minus whatever salary he negotiates with Baltimore.
Fassel's agent, Steve Rosner, has also been exploring television broadcasting opportunities for his client. Fassel didn't return a telephone call seeking comment.
"We've talked about some parameters," Billick said. "When Jim has that time to step away a little bit and reenergize, we'll readdress it."
Aaron Wilson writes for the Carroll County Times.