General manager John Mozeliak said the 29-year-old Lohse was flying in from California and would undergo a physical on Friday at the team's spring training site. The exam is unlikely to include pitching because Lohse threw a 75-pitch bullpen session on Wednesday.
"If it were a perfect world, we wouldn't have had to go down this path," Mozeliak said. "But it's not and we're going to need someone to pitch every fifth day.
"At some point, we may be dealing with a strength instead of a weakness."
Lohse can earn an additional $500,000 in performance bonuses: $100,000 each for 160, 170, 180, 190 and 200 innings. He would get a $500,000 payment if he's traded, and the Cardinals did not include a club option in the deal, perhaps reflecting the pitcher's leverage in the transaction.
Lohse was 9-12 with a 4.62 ERA with the Cincinnati Reds and Philadelphia Phillies last year, throwing 192 2/3 innings. He has made 30 or more starts five of the last six seasons.
"You look at the start of the season and there's a need, and every game counts," pitching coach Dave Duncan said. "I think we picked him up under the right circumstances and I'm happy to have him."
Clement threw batting practice for the third time on Thursday but there's no timetable for his first start following shoulder surgery that sidelined him last season. Pineiro is to resume throwing on Friday after missing his last scheduled start due to tightness below his shoulder.
Chris Carpenter and Mark Mulder also are rehabbing from surgery. Mulder could return in May and Carpenter in July. Without Lohse, the Cardinals were looking at a rotation of Adam Wainwright (14-12), Braden Looper (12-12), swingmen Todd Wellemeyer (3-2) and Brad Thompson (8-6) and Anthony Reyes (2-14).
At some point, the Cardinals may have a glut of pitchers. Duncan would like that problem.
"Whoever's the best," he said, "keeps pitching."
Clement, who missed last season after undergoing shoulder surgery in 2006, threw 39 pitches in his third batting practice session and Duncan said he'd need at least one more time out before the team would consider giving him a spring start.
"I thought he turned the corner," Duncan said. "His velocity was better, the movement on all of his pitches was good and he threw more strikes than he's thrown in any of his outings. He was excited about it, I was excited about it."
Lohse has a career record of 63-74 with a 4.82 ERA, playing his first six seasons with the Minnesota Twins. He won 14 games for the Twins in 2003 and 13 in 2002.
Lohse has allowed 1302 hits in 1164 innings over his career, but Duncan has always been impressed with the pitcher's live arm. He's had success with several pitchers who came to St. Louis with mediocre career numbers, including Woody Williams and Jeff Suppan, although Kip Wells didn't work out last year. Now comes Lohse, who hasn't had a winning season since 2003.
"It's never reflected the type of ability he has," Duncan said. "Maybe the time is right for him to reach a level of success that his physical ability should allow him to. When I knew more about what it would take to get him, I felt like he was a better fit for us."