The Tampa Bay Rays put opening day starting pitcher Shane McClanahan on the 15-day injured list last week.

It appears he'll be sidelined much longer than just 15 days.

Rays manager Kevin Cash told Marc Topkin of The Tampa Bay Times on Tuesday that McClanahan is "highly unlikely" to pitch again this season.

McClanahan has been seeing several specialists to examine his injured left forearm, and is slated to visit at least one more before a decision is made on whether he'll need surgery.

Surgery options include a loose body removal, a flexor tendon procedure and Tommy John surgery, which typically requires at least 12 months of recovery for pitchers.

McClanahan landed on IL last Thursday, one day after he left his start against the New York Yankees after four innings because of what was later described as left forearm tightness.

The 26-year-old got off to a sensational start to the season, going 11-1 with a 2.12 ERA with 97 strikeouts over 89 1/3 innings in his first 15 starts, but hasn't won since while battling tightness in his mid-back.

In his last six starts, the two-time All-Star is 0-1 with a 7.36 ERA, pitching fewer than four innings in four of those outings.

He was instrumental to Tampa Bay's fast start to the year, as the Rays were a major league-best 51-22 and owned a six-game lead over the second-place Baltimore Orioles atop the AL East at the time of McClanahan's last win on June 16.

Since then, however, they have MLB's eighth-worst record at 17-24, and enter play Tuesday three games back of the division-leading Orioles.