The deal is pending physicals by the A's players, the Denver Post reported in Tuesday's editions.
According to the newspaper, Holliday will fly to Oakland on Tuesday to meet with club officials. Barring any unforeseen medical issues -- Smith underwent elbow surgery last month -- Holliday will join the A's.
"I can't tell you how much I appreciated how me and my family were treated in Denver by the fans and the people behind the scenes in the organization. They were so important. And that's the saddest thing," Holliday told the Post.
"You build relationships that aren't going to go away, but they will change. Getting a chance to play with Todd (Helton) for five years, to play with Garrett (Atkins) and Tulo (Troy Tulowitzki), and (Aaron) Cook and (Jeff) Francis, all the guys, I really appreciate having that opportunity."
Both the Rockies and A's have declined comment. But Smith also confirmed to the Post that he's headed to Denver.
"It's a little sad to leave Oakland, but the sweet end of the deal is that I am getting an opportunity in the National League," he said.
CBS Sportsline, citing a source, said the Rockies are expected to deal Street. The report mentions the Cardinals, Mets, Tigers, Indians and Rays as teams looking for a closer. A source with knowledge of the situation told MLB.com that the Rockies are still intending to use Manuel Corpas as their closer, and indications are Street will be dealt.
Holliday will earn $13.5 million in 2009, but the Rockies decided to make a deal when they concluded they could not sign him to a long-term contract the way they had in recent years with pitchers Aaron Cook, Jeff Francis and Ubaldo Jimenez; right fielder Brad Hawpe; and shortstop Troy Tulowitzki. An attempt to reach such a deal, reportedly for four years and $68 million, was unsuccessful last spring. Holliday is eligible or free agency after the 2009 season.
Holliday is a career .357 hitter with 84 home runs, a .423 on-base percentage and .645 slugging percentage at Coors Field. But on the road, he has hit .280 with 44 homers, a .348 OBP and a .455 SLG.
In lieu of signing Holliday at an affordable price, the Rockies acquired late-inning relief help in Street, a potential rotation member in Smith and young outfield talent in Gonzalez, who entered 2008 as the top-ranked prospect in the Athletics' chain, according to Baseball America.
The most notable name headed to the Rockies is that of Street, the 2005 American League Rookie of the Year. Street, 25, appeared in 63 games and went 7-5 with 18 saves in 25 chances in 2008 but lost his closer job to Brad Ziegler late in the season.
If the Rockies don't make another deal, Street, a right-hander, would help shore up a bullpen that is likely to lose three-time All-Star Brian Fuentes to free agency. Corpas signed a four-year contract last offseason but lost his closer job and had an up-and-down 2008. However, Corpas improved as the season progressed, and the team is prepared to restore him as closer.
Street made $3.3 million in 2008 as a first-time arbitration-eligible player.
The Athletics originally acquired Smith and Gonzalez in the deal that sent pitcher Dan Haren to the D-backs.
The Rockies will see if Smith, who turns 25 on Dec. 22, is part of the answer to the club's quest to increase the starting rotation's talent level. Smith went 7-16 with a 4.16 ERA in 32 starts and 190 1/3 innings for the A's, and underwent surgery after the season to remove "loose bodies" from the elbow of his throwing arm.
Gonzalez, 23, from Venezuela, hit .242 with four home runs and 26 RBIs in 85 games last season as a rookie. He also hit .283 with four homers and 28 RBIs at Triple-A Sacramento. To further show he is ready, however, Gonzalez will have to curb his strikeouts. He fanned 81 times in 302 Major League at-bats.
The Rockies gained flexibility because Gonzalez can play center field, which gives them added coverage should they trade Willy Taveras, the leadoff man and center fielder the past two seasons. The Rockies were prepared to put right-handed-hitting Ryan Spilborghs in center, but now they can place Spilborghs in Holliday's old spot in left. The Rockies also have one of their prospects, left-handed-hitting Seth Smith, bucking for outfield playing time.
Holliday finished second in National League Most Valuable Player voting in 2007 while leading the Rockies to the World Series, where they were swept by the Red Sox. Holliday hit .340 with 36 homers and 137 RBIs in 158 games during the regular season, scored the winning run in the 13th inning of the one-game playoff for the NL's Wild Card berth and earned MVP honors in the NL Championship Series sweep of the D-backs.
Last season, Holliday hit .321 with 25 homers and 88 RBIs for the Rockies, who struggled throughout the season and finished third in the NL West. He missed 14 games in May with a left hamstring strain. He also homered during the All-Star Game at Yankee Stadium.
The Holliday trade could be the start of an active offseason for the Rockies, who also are looking to deal Taveras and have dangled third baseman Garrett Atkins, who also has not signed a multiyear deal and could be traded for pitching help.