Seahawks offensive coordinator Darrell Bevell is a big supporter of Jackson.
Jackson was the Seahawks' starting quarterback in 2011 but lost his job to Russell Wilson last summer. The Seahawks traded him to the Bills before the start of last season.
In the end, Jackson never received a shot in Buffalo after being acquired by the Bills in a trade with Seattle in August. The seventh-year player spent all of last season as Buffalo's third-string quarterback. Jackson then signed a one-year contract to return to Buffalo in February, believing he would have an opportunity to compete for a starting job.
Jackson was selected in the second round of the 2006 draft by Minnesota. The Alabama State product has appeared in 51 games, and has starting experience with both the Vikings and Seahawks. Jackson's best season came in 2011, his one and only year with Seattle. He went 7-7, putting up career highs with 14 touchdowns, 271 completions and 3,091 yards.
It is not known what the expected signing of Jackson would mean for Brady Quinn, who was signed to be the backup this offseason.
The Seahawks do have an opening for a quarterback. They released Josh Portis in May.
Information from ESPN NFL Insider Adam Schefter, ESPN.com senior writer John Clayton and The Associated Press was used in this report.