The 28-year-old striker rejoined the Shrimpers on loan from Coventry in March, coming after a three-year stint at Roots Hall between 2004-07 saw him score 63 goals in 134 games.
Eastwood enjoyed League Two play-off success in his first season, scoring the only goal to see off Northampton in the semi-finals before hitting the net in a 2-0 final triumph over Lincoln at the Millennium Stadium.
His goals helped seal automatic promotion to the Championship the following year and, having now returned to Essex, he is looking to repeat his past achievements when Southend travel to Crewe in the first leg of their League Two play-off semi-final this evening.
"I had some good times here before and got promoted, double promotion in two years, so hopefully this can be the third," Eastwood told the club's official website.
"One thing I've certainly been thinking about over the last year or two is that I'd love to play at Wembley before my career ends and hopefully this is my chance."
Crewe boss Steve Davis, who is chasing a triumphant end to his first season in league management, takes encouragement from a bitter play-off experience during his playing days.
"I wasn't a big fan at first all those years ago when I was at Burnley and we got knocked out to Torquay," he said.
"We got beaten in the semi-final. I think we finished something like 21 points in front of them and we went out to them.
"We (Burnley) finished where Southend are and they finished where we are, so that tells you a story about the play-offs."
Now the 46-year-old concedes he is a fan of a format that might be ideally suited to an Alex side enjoying a 16-match unbeaten run.
He added: "It keeps the middle section of the league going, it keeps it exciting for the fans and it gives the players a challenge.
"It gave us something to go for. We kept talking about the run we had to go on and we managed to do it."