Gonzalez will wear uniform No. 47, the same number he wore in Oakland. Gonzalez acknowledged he was "a little nervous" when trying on his new jersey in front of the media. He said the trade didn't hit him until Tuesday when he attended a Washington Capitals game.
"Yesterday, it hit me that I was home, when I was at the Capitals game and I got all the love in the world from all the fans," Gonzalez said. "I think it sets a tone that we're ready, that we're going to come out here swinging for the fences, and we're going to go out there and shut teams down.
"I think it's a great opportunity and a great organization to do it with. I think I'm going to be here and happy for a while."
Earlier this month, Washington agreed to terms with Gonzalez on a five-year, $42 million extension -- with options for 2017-18 -- thus avoiding salary arbitration.
Both parties began talking about a new deal right after the trade was made.
"One of the main reasons we wanted to [sign Gonzalez to an extension] was that we are satisfied and convinced that this is the type of person and player that we want on the mound for us and in the clubhouse," general manager Mike Rizzo said. "We have done a lot of homework. I've known Gio for a long, long time. I've known the scout who signed Gio for a long, long time.
"We are convinced of the makeup, we are convinced of the character. We scouted the player extensively. We are convinced of the skill set, the talent level. It gives us cost certainty as a franchise. It gives the player some ease of mind that he is there. He doesn't have to worry about finances. He doesn't have to worry about arbitration. We felt it was good value for us to lock him up long-term. We are extremely excited about having him through his arbitration years and three free-agent years if we exercise the option. So he is going to be part of the furniture for a long time. We feel we got ourselves a top-of-the-rotation, powerful left-handed pitcher to complement our right-handers."
Gonzalez joins a rotation that will include Stephen Strasburg, Jordan Zimmermann, John Lannan, Chien-Ming Wang and Ross Detwiler.
"I feel honored to be a part of it -- with the names out there," Gonzalez said of his new teammates. "You look at our rotation and lineup ... I think it's going to be a fun season with the Washington Nationals.
"It's definitely going to be a work in progress. This is the exciting part where I get to watch Zimmermann, Strasburg, Chien-Ming Wang go out there and pitch. I get to study off these guys every night."
Last season, Gonzalez was 16-12 with a 3.12 ERA and had 197 strikeouts in 202 innings. His 8.8 strikeouts per nine innings ranked third among all qualifying southpaws.
In Gonzalez, the Nats have a hard-throwing left-hander to face National League East sluggers such as Phillies second baseman Chase Utley and first baseman Ryan Howard.
With Gonzalez pitching in the NL, his biggest adjustment will be swinging the bat. He is 0-for-7 during his big league career.
"From the highlights of my swing, it's not the prettiest," Gonzalez said. "I definitely want to say I will try to make an adjustment. I will try to do my best trying to bunt it down and try to slow it down running to first base and not pull anything."
Getting Gonzalez was a top priority for the Nats after they were unable to reel in left-hander Mark Buehrle, who signed with the Marlins. It marked the fourth time in his career that Gonzalez had been traded. He had Minor League stints with the White Sox and Phillies. During the first three trades, Gonzalez was a throw-in. This time, he was the major player. He tried not to pay attention to all the trade rumors before the deal was completed.
"It was one of those situations where you had to put [the rumors] away," Gonzalez said. "If I sat there every five minutes [at a computer] refreshing, refreshing, I was going to go nuts. I would probably be up here with grey hair. ... It was situation where it was becoming fun, but at the same time, I was stressing out a lot. This was too much to handle, especially for me. I was always at the back end [of a trade]. I was never the main guy of a trade [until recently].
"... I was still training hard, I was still working. I was still preparing myself just in case nothing happened, but when it happened, it hit me to the point where I was like, 'That's it. No more green and gold.' It's time to represent a new city, a new team, and I'm going to do what I tried to do in Oakland: I'm going to pass it down here and try to win a title."
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.