A month into his audition for the Orioles' long-term closer role, Jim Johnson has learned quickly about the difficulty of pitching the ninth inning.

"I make good pitches and they get hit, and I make bad pitches and they get hit," Johnson said. "I give up runs at the worst time right now. That's just part of pitching at the end of the game."

In Wednesday's 4-2 victory over the Tampa Bay Rays, Johnson surrendered a game-tying homer to Ben Zobrist, blowing his second save in eight opportunities since taking over the closer's spot from the traded George Sherrill.

Since Sherrill was traded to the Los Angeles Dodgers on July 30, Johnson has a 7.16 ERA in 16 outings, though only eight were save situations. He has pitched a perfect inning in four of 16 outings and given up a run in six.

"I'm in a funk. Hitters go in slumps, pitchers go in funks sometimes," said Johnson, who has allowed eight home runs this year after giving up none last year.

Before Thursday night's game, Johnson watched video with pitching coach Rick Kranitz, who detected minor flaws in Johnson's delivery. Neither Johnson nor manager Dave Trembley thinks the reliever's recent struggles are related to the pressure of the closer's role. Johnson's problems started earlier, as he gave up runs in three of his previous four outings before being named closer.

"I think he's very competitive," Trembley said. "I think he wants to be the guy. Maybe he's trying to force it. I know he's had a couple of rough ones - the one against Cleveland and the one [Wednesday] night. But he's still closed six out of eight. You're looking for perfection all the time and it doesn't happen. I think going forward here, the last games of the season, he's the ninth-inning guy. We have to see if he can do it or not."

Mickolio's season over
Still unable to pitch with inflammation in his right shoulder, reliever Kam Mickolio was officially shut down for the rest of the season and placed on the 15-day disabled list. Mickolio, who had a 2.63 ERA in 11 games for the Orioles this season, acknowledged that he was disappointed with the club's decision to put him on the DL.

"At this point, it feels like there's no need, but it what it is," said Mickolio, who will remain with the club through the homestand.

Asked why the Orioles placed the reliever on the disabled list this late in the season, Trembley said, "The games count in September just as much as they do in July and August, so if guys are not able to perform or participate, they're going on the DL."

Mickolio, 25, described his condition as a "dead arm" but said he didn't think it would get in the way of his preparation for the 2010 season, when he's expected to occupy a key role in the back of the bullpen.

"Hopefully, I'll come back stronger," Mickolio said.

Two more for Tillman
Trembley confirmed that right-hander Chris Tillman will make two more starts before he is shut down for the season. Tillman will pitch at Toronto on Monday and next weekend at Cleveland before his rookie season ends.

Tillman, 21, has pitched 154 2/3 innings this season after throwing 135 2/3 last year.

Around the horn
Matt Wieters and Nolan Reimold have hit two of the three game-ending homers by American League rookies this season, according to the Elias Sports Bureau. The Indians' Luis Valbuena has the other. ... Reimold returned to the lineup after a two-game absence.