Havlat, 32, has one-year left on his contract beyond this season, and carries an annual salary cap hit of $5 million.
The native of Mlada Boleslav, Czech Republic, recently returned from a pelvis injury and was recently scratched from the lineup.
In eight games with the Sharks so far this season, Havlat has registered one goal and one assist while playing on San Jose's third line.
Senators GM Bryan Murray has been looking for a second-line scorer for the last few weeks and is believed to have inquired about several other players around the league, in addition to Havlat.
Havlat owns a no-movement clause, but the Sun claims he would be willing to waive it to go back to Ottawa, where he spent the first five seasons of his career after being drafted 26th overall by the club in the 1999 NHL Entry Draft.
The Rangers are also in the market for a top-six forward, but do not have the same cap flexibility as the Senators.
Rangers defenseman Michael Del Zotto, who was scratched from the team's last two games, is believed to be available for trade.