Lee, the 2008 American League Cy Young Award winner who was expected to be the club's No. 2 starter behind last year's AL Cy Young runner-up, Felix Hernandez, has a right lower abdominal strain that puts him in jeopardy of beginning the season on the 15-day disabled list.
Lee traveled to Seattle to be treated for the strain, which was diagnosed and treated by team medical director Dr. Edward Khalfayan. Lee underwent an ultrasound exam and received a platelet rich plasma (PRP) injection, which promotes healing. He will be re-evaluated in seven days.
Lee already was in danger of missing the first five games of the season after being suspended for throwing a pitch near the head of D-backs catcher Chris Snyder in a game against Arizona in Tucson on Monday. According to Mariners manager Don Wakamatsu, Lee and his agent, Darek Braunecker, were working on filing an appeal to reduce the suspension.
Coincidentally, the same incident in Monday's game might have led to the injury and the suspension.
Lee, who experienced pain in the area during a Thursday bullpen session, told Wakamatsu that he thought he might have suffered the injury during a first-inning collision with Snyder on Monday. The two ran into each other when Lee ran to cover home plate on a Chris Young RBI single and words appeared to have been exchanged.
Two innings later, Lee went inside with one pitch and then threw another that sailed above Snyder's head, close to hitting his helmet. Home plate umpire Brian Knight immediately ejected Lee and both dugouts and bullpens emptied toward the mound, but no punches were thrown.
After that game, Lee stated that he didn't intend to throw the ball at Snyder.
"I was trying to go inside, a couple got away from me, and the guy hitting got mad and came towards the mound, and I got thrown out of the game in the process," Lee said at the time. "That's it in a nutshell."
Lee also said Monday that he didn't think the first-inning collision was anything to mention, since he wasn't aware of how it happened in the first place.
"All I know was I was rolling on the ground," Lee said. "I got knocked down. I didn't see it all. I was looking at the play."
Now the Mariners have a greater concern than possibly having to wait five days for the services of one of their key offseason acquisitions.
Before Monday, Lee was on schedule to pitch in Oakland on April 6. But if he has to open the season on the DL, the team probably will break camp with both starters who were battling for the No. 5 spot in the rotation, Jason Vargas and Doug Fister.
"It's not a good feeling," Wakamatsu said. "Obviously, we were extremely excited about having him in the rotation. Now we have to evaluate and see where we're at."
Wakamatsu wouldn't rule out Lee starting the season on time, but it isn't likely considering the unpredictable nature of the injury and the fact that Lee hasn't thrown more than 2 2/3 innings in camp. He had been slowed a bit by a minor foot surgery before the team reported to Spring Training.
Also, this isn't the first time Lee has suffered a similar setback.
Lee, then with Cleveland, began the 2007 season on the 15-day DL with a strained right abdominal muscle and finished the year with a 5-8 record and 6.29 ERA for the Indians. He also made eight starts for Triple-A Buffalo that year.
Lee also spent the first two months of the 2003 season on the DL with a lower abdominal strain and sports hernia. He went 3-3 with a 3.61 ERA for the Indians that year and had the hernia operated on that October.
"We'll let it run its course and re-evaluate it in a week," Wakamatsu said. "He might feel like a million dollars."
But even if that's the case and Lee begins throwing on March 26, it's doubtful that he could build up the desired pitch count to get ready for the first week of the season. Still, the Mariners are holding out hope that it's a minor malady.
"Sometimes you get a tweak here and there," Wakamatsu said. "I think it's good we caught it when we did."
Added general manager Jack Zduriencik, who orchestrated the trade that gave up three prospects in a three-team deal for Lee in January: "We are hoping for a speedy recovery and look forward to him returning."
Wakamatsu had already said the team was planning on mapping out the starting rotation over the first month of the season as early as the club's next off day in Arizona on March 30, and that the suspension had confused things to the point where he called it a "mess."
And now this.
"There are a lot of decisions to make," Wakamatsu said. "This isn't one we were prepared for."
Doug Miller is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.