Dombrowski said he's not surprised at least some Tigers fans weren't happy when they trade was announced because the team traded the "known for the unknown."
"People in general don't like those type of moves," he said.
The Tigers still have Scherzer, Justin Verlander and Anibal Sanchez atop their rotation.
"This is an exciting day for the Washington Nationals," general manager Mike Rizzo said in a statement. "We feel we've added a talented, young veteran to our starting pitching corps. Doug is battle-tested through playoff experiences, and the depth he brings to our staff is exceptional. We are thrilled to welcome him aboard."
The 22-year-old Ray was 6-3 with a 3.11 ERA for Class A Potomac and was 5-2 with a 3.72 ERA for Double-A Harrisburg, giving the Tigers a pitcher they think will start the season at Triple-A Toledo with the ability to possibly pitch in the majors if needed in 2014.
Krol made his major league debut in June for the Nationals after they acquired him from Oakland. The 22-year-old lefty was 2-1 with a 3.95 ERA in 32 games in Washington.
The 25-year-old Lombardozzi hit .259 with two homers and 22 RBIs in 118 games for the Nationals last season. The switch-hitting sparkplug played 48 games at second base, 23 in left field and four games at third base in 2013. He will replace Ramon Santiago on Detroit's roster next season.
"This was not an easy trade for (the Nationals) to make, either," Dombrowski said.
Washington went into the offseason hoping to add another starter it could count after having some uneven results from Haren last season and Edwin Jackson in 2012. Both of those right-handers were seen as short-term solutions and they ended up leaving as free agents after pitching for the Nationals for one season.
Haren essentially replaced Jackson. Fister now essentially replaces Haren, who recently signed with the Los Angeles Dodgers after going 10-14 with a 4.67 ERA for Washington.
Also, the Nationals and Ross Ohlendorf agreed to a $1.25 million, one-year contract. The right-hander went 4-1 with a 3.28 ERA in 16 games, seven starts, last season. The 30-year-old Princeton star can earn up to $3 million in bonuses tied to starts, innings pitched and relief appearances.
AP Sports Writer Howard Fendrich contributed to this report.
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