ST. PETERSBURG, Fla. -- Josh Beckett will take another step toward pitching again on Tuesday, when he throws to Gulf Coast League hitters in his first rehab assignment since going on the 15-day disabled list on May 19 with a bad back.

Still, as he sat in the Tropicana Field visitor's clubhouse on the cusp of easing back into active duty, Beckett's frustration regarding how he will end up missing more than two months wasn't hard to find. And most of the dismay still stemmed from that night back back in New York on May 18.

That evening, on a fifth-inning pitch to Alex Rodriguez, Beckett slipped, threw a few more pitches and then left the game. Forty-nine days later, he still hasn't pitched in another game.

"I would have been fine if it didn't rain the whole game in New York," he said prior to the Red Sox' series-opening game against the Rays Monday night. "I was well enough to get through that start. I wasn't 100 percent, but if I could have gotten through that start without re-injuring my back and then get five more days, things would have been different.

"It just pisses me off because I feel like we could have controlled it. We shouldn't have played that game. It's unfortunate that we played that game and I just happened to line up to pitch that day. But start, stop, start, stop doesn't bother you when you're healthy. I'm getting ready, getting ready, getting ready and then we're stopped for 45 minutes. The field drains fine. The mound drains fine. But what happened with that clay is that it balls up and when it balls up that's when the slips happen."

What Beckett took out of the situation was the importance of not taking any chances, a notion that has allowed him to get through his recent down-time.

"We're still going one day at a time. We're not rushing this thing back. That's why we ended up with this much time, because we did do that," he explained. "We didn't do the right thing, and that's partially my fault because I didn't speak up. I felt if I just kept getting through things then they would get better, but I only made things worse."

Beckett had originally injured his back 10 days earlier while taking batting practice in preparation for interleague play. The ailment forced the starter to miss a start, giving him 1 1/2 weeks of rest prior to appearing at Yankee Stadium.

Beckett experienced yet another setback on May 28 when, while throwing a bullpen session, the righty experienced pain in his right lat muscle. The result was the Red Sox shutting their Opening Day starter down for two weeks, not allowing him to throw at all.

"We had to take two weeks off. I don't think we would have been in that position if we… like I said, it was my fault for not speaking up," Beckett said. "I remember throwing [at Tropicana Field] one day and thinking there was no way I should be throwing. That's how we ended up with five weeks off because I wasn't smart enough to just say, 'This just isn't helping.'"

Beckett wants to make it clear that he was well enough to make the start in New York, and most likely would have used it as a springboard to better health if not for the conditions.

Now, having missed the equivalent of 10 starts, Beckett is left looking for optimism in the future, both near and far. After all, two of the best postseason runs in history -- in 2003 and '07 -- came after missing time during the regular season.

"I think I look at '03 a little more because that was a longer period of time and a little bit more of a down-time injury," he said, referencing an elbow strain that forced him to miss nearly two months (May 7-July 1). "In 2007 (when he went on the 15-day disabled list with an avulsion to his pitching hand) I remember throwing two five-inning simulated games in my 15 days. But both times I absolutely felt stronger (in October)."

Red Sox manager Terry Francona, for one, believes Beckett has the look of a pitcher ready to return.

“He looks pretty good,” Francona said of the starter, who is expected to throw in the vicinity of 55 pitches Tuesday. “The other day he was letting it go pretty good. The command is going to take a little while , but he was letting it go pretty good. You can tell he feels good.

“When he’s had problems pitching, the times he’s been on the borderline thinking about, ‘Am I OK,’ he’s had a hard time. When he goes out there and knows that he’s OK then he can go and everything is fine. I can see the difference in the demeanor.”