The Celtics may still have interest in re-signing Ray Allen, but they are on the verge of signing an insurance plan, in guard Jason Terry.

Terry is on the verge of closing in a three-year contract with the Boston Celtics, sources close to the situation confirmed Tuesday. The offer is believed to be a full mid-level exception of $5 million annually. But the sources insist that the Celtics remain interested in Allen.

Terry has spent the past eight seasons in Dallas, having replaced Steve Nash in 2004. He won Sixth Man of the Year Award in 2009 and had a phenomenal playoff run in 2011 to help the Mavericks win the franchise's first NBA championship.

Terry, 34, averaged 15.1 points and 3.6 assists last season and shot 37.8 percent from the 3-point range. Fourth on the NBA's all-time list for 3-pointers made, Terry is a 38-percent 3-point shooter for his career and has averaged 16.1 points per game.

Terry over his career has also been known as a wiry defender and capable transition player. His spot-up style would work nicely with Rajon Rondo's drive-and-dish game.

Terry's emergence as a Celtic calls into question the team's commitment to Mickael Pietrus, who is still waiting for a call from the team.According to Pietrus' agent, Bill McCandless, the tough-defending swingman has been contacted by four teams and has had direct contact with officials from two of those teams, including one coach.