DETROIT -- Nick Blackburn is heading back to Class AAA Rochester.

The Twins optioned the righthander today, promoting righthanded reliever Casey Fien to take his roster spot. Fien was added to the 40-man roster and will arrive in Detroit tonight, although he probably won't be available to pitch until Thursday.

Fien went 2-5 with a 4.30 ERA and had nine saves in 12 opportunities for the Red Wings. He pitched two scoreless innings on Tuesday night.

Blackburn was 4-5 with an 8.10 ERA in 13 starts. His next scheduled start was Sunday, and the Twins haven't announced who will face Texas that day in his place.

Independence Day Underdogs

After a brutal start to the season, the Twins are enjoying a nice ride as they arrive at the mid-point of the season tonight.

They are 25-19 since they were sitting 10-16 on May 15. They are 4-0 in Detroit after winning the first two games of this four-game series. It's enough to make you forget that they still have the worst run differential in the majors, at -81 (329 runs scored, 420 runs allowed).

Despite all that positive momentum, they'll spend the Fourth of July as the biggest underdogs of the day. Because of this pitching matchup -- Justin Verlander vs. Brian Duensing -- a person would have to bet $2.80 to make $1 on a Tigers victory, according to one site I checked.

But the Twins are ready for the challenge.

Update: Justin Morneau is not in tonight's lineup. There's no injury; Manager Ron Gardenhire explained it as a standard night off and chance for Chris Parmelee to play. Brian Dozier also is getting the night off.

TWINS (35-45)

1. Denard Span, CF
2. Ben Revere, RF
3. Joe Mauer, C
4. Josh Willingham, LF
5. Chris Parmelee, 1B
6. Trevor Plouffe, 3B
7. Ryan Doumit, DH
8. Jamey Carroll, SS
9. Alexi Casilla, 2B

Starting pitcher: LH Brian Duensing (1-4, 4.10 ERA)

TIGERS (39-42)

1. Austin Jackson, CF
2. Ryan Raburn, LF
3. Miguel Cabrera, 3B
4. Prince Fielder, 1B
5. Delmon Young, DH
6. Jhonny Peralta, SS
7. Brennan Boesch, RF
8. Alex Avila, C
9. Ramon Santiago, 2B

Starting pitcher: RH Justin Verlander (8-5, 2.69 ERA)

Comerica Park. First pitch: 6:05 p.m. (Central). TV: FSN. Twins Radio Network

Follow along on Twitter: @JoeCStrib