Earlier this season, the Orioles rotation continually pitched deep into games only to see a shaky bullpen and a woeful offense expunge any hope of winning consistently.

Now, through the first 10 contests of the second half, Orioles starters are doing their part to contribute to arguably the worst season in modern franchise history.

In a 10-4 thumping by the Minnesota Twins on Sunday afternoon that dropped the Orioles (31-67) to 2-8 to start the second half, another young Orioles pitcher failed to give his club a chance.

This time it was rookie Jake Arrieta (3-3), who lasted just four innings, surrendering five runs on seven hits and four walks in just four innings pitched.

Arrieta, who has now struggled in both his outings since the All-Star break after throwing a one-run gem to close the first half, was wild from the beginning. He kept the Twins scoreless until the third, however, when Jason Kubel hit a grand slam to give the Twins a 4-0 lead.

It was one of four homers hit by the Twins on an afternoon that included an hour and five minute rain delay that chased the majority of the announced crowd of 17,408.

Arrieta's rough outing is part of a disturbing trend for the Orioles' rotation. Only four times in the first 10 games of the second half has a starter gone six innings or deeper. Take out Jeremy Guthrie's two quality starts, and the Orioles' rotation has worked just 36 1/3 innings in eight games, allowing 41 earned runs (10.10 ERA) and 54 hits.

In the sixth, Delmon Young and Jim Thome hit back-to-back homers against reliever Mark Hendrickson, part of a 19-hit barrage by the Twins (53-46).

The Orioles offense also stumbled, managing just five hits and one run in six innings against Kevin Slowey (8-6), who hadn't won in July and had been in jeopardy of losing his rotation spot.

Orioles leadoff hitter Corey Patterson doubled in the first and scored on a Nick Markakis sacrifice fly. The Orioles didn't score again until the ninth, when they plated three against Minnesota's Nick Blackburn, a former starter who had been demoted to the bullpen due to ineffectiveness.

The Orioles' 31-67 record through 97 games is identical to that of the 1988 Orioles, who lost a franchise-worst 107 games.

dan.connolly@baltsun.com