VERO BEACH, Fla. -- While the rest of the Dodgers had Wednesday off, Randy Wolf pitched a simulated game against Minor League hitters and made it through unscathed, but just barely.

Preston Mattingly, son of Don and a sandwich pick in last year's First-Year Player Draft, nearly drilled Wolf with a line drive, but the lefty threw his glove up in front of his chest and knocked it down.

"One-four-three," said Wolf, taking credit for initiating a double-play that had to be imagined, because Wolf had no fielders behind him. "It was a little scary, but those are the kinds of things that happen during games. It took me back to my second or third rehab start last year [following Tommy John elbow ligament transplant surgery]. A lefty hit a come-backer and it fractured my [pitching] hand. It's much better to hit the glove."

Wolf, lined up to start the second game of the season, threw 73 pitches and got up and down for five innings. He faced some of the farm system's better young hitters (Mattingly, Chin Lung Hu, Marshall McDougall) and two veteran left-handers (Larry Barnes and Luke Allen).

He was limited to 15-pitch innings, "So I tried to get the three outs in 15 pitches and make it a game," he said.

"He's right where we want him to be at this time in Spring Training," said manager Grady Little. "Thankfully, he didn't get hurt."

Billingsley in bullpen: Wolf is expected to be joined in the rotation by Opening Day starter Derek Lowe, Jason Schmidt and Brad Penny. With Chad Billingsley going to the bullpen, the primary fifth starter candidates are Brett Tomko, Hong-Chih Kuo and Mark Hendrickson, with Eric Stults and non-roster pitcher Joe Mays as long shots.

"His initial reaction was that he was glad he was on the team," Little said after breaking the news to Billingsley, who will bolster the bullpen in the middle innings, before the game is turned over to Joe Beimel, Jonathan Broxton and closer Takashi Saito.

Houlton improves: Pitching coaches have spent considerable time revamping the delivery of D.J. Houlton, who pitched a perfect inning Tuesday and has allowed only one run in 4 2/3 innings with six strikeouts and one walk.

"His last two games have been his best," said Little. "It looks like he's applying what they're telling him when he's on the mound and gets a chance to pitch."

Houlton has appeared in only three games this spring and there seems to be no room on the staff for the right-hander, who made 19 starts for the Dodgers in 2005 as a Rule 5 pick but spent all of 2006 at Triple-A.

Tatis released: Former Major League infielder Fernando Tatis, reassigned to Minor League camp Sunday, never reported and was released by the club Wednesday.

Coming up: When play resumes Thursday, the Dodgers will have a split doubleheader, traveling to Jupiter for a day game against St. Louis (10:05 a.m. PT), then hosting Washington in a night game at Vero Beach (4:05 p.m.). Hendrickson starts against the Cardinals and Schmidt starts against the Nationals.