Pat Gillick, Toronto's general manager, wasn't happy then, but he looks on the deal more favorably now.
With Dave Stieb unable to pitch since May 22 because of a herniated disk, Guzman, 24, has been Toronto's savior.
He pitched 5 2/3 innings of the 5-2 victory over the Minnesota Twins in Game 2 of the American League's championship series after going 10-3 with a 10-game winning streak in 19 regular-season starts.
"He's going to be a horse," said Toronto pitching coach Galen Cisco, meaning a thoroughbred.
There was considerable doubt for a while. Signed by Ralph Avila, the Dodgers' top scout in the Dominican Republic, Guzman, a longtime friend and neighbor of Ramon Martinez, battled his control for three seasons in the Dodger farm system and three more in the Blue Jay organization.
The breakthrough occurred last winter. The hard-working Guzman--he runs stadium steps two or three times a week--found a consistent release point and went 10-1 in the Dominican.
Said Cisco: "He can still miss the catcher at times, but he knows how to correct himself now."
The Blue Jays got Guzman in a trade that sent Mike Sharperson to the Dodgers on Sept. 22, 1987. Some names had been kicked around and it came down to Guzman and Offerman, teen-agers who had not played in the United States.
"We wanted Offerman and thought we had the choice," Gillick said of his negotiations with Fred Claire, the Dodgers' executive vice president. "In the end, Fred insisted it was his choice and gave us Guzman.
"I wasn't happy. It was Fred's first year (as general manager), and I don't think he really knew that much about Offerman until we showed interest. And he then figured that maybe he'd better not trade him.
"Guzman had a good arm. We knew that, but a lot of young pitchers have good arms without ever putting it together."
The Blue Jays were still so uncertain about Guzman that they exposed him to the Rule V draft last December. Any of the 25 other teams could have selected him for $50,000, but none did.
"How smart are we?" Gillick said of the decision not to protect Guzman. "I mean, this was a situation in which the kid simply found himself last winter."
Sharperson has given the Dodgers what they were looking for--improved depth at two or three positions.
Said Claire: "We knew Guzman had a very good arm, but we felt he was several years away and would have to acquire command, always an unknown.
"The fact that 25 teams passed on him only last December is a reflection of the scouting reports. The fact that he wasn't protected is a reflection of what the Blue Jays thought about him, and they knew him better than anyone.
"Sometimes you've got to be lucky--or maybe unlucky, depending on how you look at it."
Considering Guzman's success and the questions surrounding Offerman in his bid to become the Dodger shortstop, the Blue Jays might have been lucky in several ways.
Luck and hard work have been Guzman's allies in his emergence from what he described as an impoverished environment in the Dominican Republic.
"Ramon was always the better pitcher, the more natural pitcher," Guzman said of his friend. "I had to learn, make mistakes, get help. I always thought I could make it, but never in my dreams did I think it would turn out like this. I think the Lord has been with me."
The speed guns clock Guzman's fastball in the low- to mid-90 m.p.h. range. Is it under control now? In 138 2/3 innings after his June 4 recall by the Blue Jays, he walked 66, struck out 123 and had a 2.99 earned-run average.
He is also 3-0 in four starts against the Twins and may be brought back to pitch Game 5 Sunday instead of Tom Candiotti, who irked Manager Cito Gaston in Game 1 by favoring a curveball over his noted knuckler.
"He got beat on his second-best pitch," Gaston said.
The rotation hasn't been changed yet, but Candiotti, asked about it Thursday, said, "I know they want Guzman (who is scheduled for Game 6) out there as much as possible. I'm preparing for Sunday, but if Juan pitches, I'll be rooting for him to win."
Guzman said he was excited but not nervous in the ear-piercing Metrodome Wednesday. The noise, he said, was louder than anything he had ever heard.
"At least, the fans weren't throwing anything at me, like they do sometimes in the Dominican," he said. "It can get wild."
Conceivably, there may be fans in Los Angeles tempted to throw aspersions at the home team for having traded Guzman to a team that didn't want him but now wouldn't part with him.