PAWTUCKET -- Mark Prior feels like he’s working his way to the majors for the first time in his career. 

Of course, a call to the bigs wouldn’t be the first such occurrence for the second overall pick in the 2001 draft, but this is the hardest he’s ever had to work for it. The former Cubs phenom hasn’t played in the majors since 2006 due to a rash of injuries, and the Red Sox are the fourth organization with which the right-hander has tried to make a comeback since leaving the Cubs. 

“It’s a lot harder this time around,” Prior said Wednesday at McCoy Stadium. “When I was coming up with Chicago [in 2002], I don’t want to say it was a guarantee that it was going to happen, but I knew I was going to get to the big leagues. I knew, physically, I could get guys out. I know, physically, now I can get guys out, but things are different. Is there an opportunity? Is there a place that you would slot in? 

“Back then, I was their high draft pick. They were going to make room. That’s not the situation here. That’s not the situation for most people who get to the big leagues. They’re not making room. [Will] Middlebrooks, they make room for guys like that. It’s definitely a different dynamic than it was back in 2002.”

Still just 31 years of age, Prior knows that he doesn’t have the velocity of his 22-year-old self, but he’s confident that he’s always been capable of getting guys out. While that may be the case, his biggest struggle in his career has been staying on the mound. Since going 18-6 with a 2.43 ERA and 245 strikeouts in 2003, Prior has had to deal with arm injury after arm injury, most notably shoulder problems. 

After dealing with a strained shoulder, a strained oblique and shoulder tendinitis in 2006, Prior missed the entire 2007 because of shoulder surgery. He eventually had another shoulder surgery in 2008, and his comeback attempt with the Yankees last year ended after one Triple-A appearance when he tweaked his groin.

“Obviously, there’s always going to be a physical question mark with me. I’m honest about that with myself, and I recognize it and respect what I have to do to put myself in position to perform out there,” Prior said. “But there was obviously the big question: Can I still get guys out? I felt that was more of a confidence thing for me that I had to get over last spring, and I felt like I did that. I felt like I showed that I could compete at the big-league level. I know it was spring training, but I was still getting big-league hitters out late in the spring when they’re getting ready for the season.”

Prior feels he can still pitch and remains confident in his repertoire, and now that he feels healthy he can use his stay in Pawtucket to hopefully get the attention of the big league club. He’s off to a good start so far.

After signing with the Sox last month and pitching in extended spring training, Prior got the call to Pawtucket last weekend. He’s made two appearances out of the bullpen for the PawSox this week since the promotion, allowing two hits, no runs and a walk while striking out six batters over 2 2/3 innings. Five of those strikeouts came on Wednesday in his 1 2/3 innings of work in relief of Daisuke Matsuzaka. 

“I felt like [Tuesday], I was kind of seeing my spots and felt comfortable out there. Saturday in Lehigh [his PawSox debut in which he threw a scoreless inning with one walk], things were a little uncomfortable, but last night felt good, and it was good to come into a situation where a runner was on base and another runner got on base and get out of it.” 

Prior feared that he might not even be playing affiliated baseball this season, but a longtime friendship helped lead him to the Red Sox. After his groin healed, Prior texted Dave Finley, a friend from San Diego who currently serves as Boston’s director or player personnel, to pick his brain about what he should do in the coming season. Finley had something other than independent ball in mind. 

“I just said, ‘Hey, my groin is healed up. I’m ready. I’ve been facing hitters,’” Prior recalled. “I was more or less texting him for advice, like, ‘I’m thinking of going to independent ball again. What do you think? What do I have to do?’ It’s hard to get back into affiliated ball, especially for someone who has been out injured. People know my track record and my history. 

“He happened to be back in San Diego after spring training and came by to watch a bullpen and said, ‘You know, if you want to come down for like a three-week evaluation period, no strings attached, no guarantees.’ I said, ‘Yeah, I’ll do it.’ I went down there and obviously caught their attention. They liked what they saw. It’s as simple as that.”

Simple is the opposite of what Prior’s career has been. He was once a dominant prospect turned 22-year-old ace, but it’s been years since he’s taken a major league mound. Admitting to the cliché, he stresses that he’s been through enough to know to take his comeback day-by-day. The light at the end of the tunnel is Boston, and if he can stay healthy and force his way back to the majors, he’ll have not only pulled of the improbable, but proven a lot of other teams wrong.

“I want to be in Boston, just like everybody else in here,” he said. ”They want to be in Boston. I’m not naïve not to know what that bullpen is doing is unbelievable. I’m pitching here to get to Boston. I want to be there. I think I can help them when I do get there. Whatever that role might be, to me, at this stage of my career, it’s about getting back to the big leagues and having the opportunity to win a championship. 

“When you’re in your early 20s, you’re like, ‘Yeah, I want to win a championship,’ but you don’t -- I remember Eric Karros told us, when we went to the playoffs in ’03, ‘Enjoy it because you never know when the opportunity is going to present itself.’ … I want to get to the big leagues, but if I can get to the big leagues and have a shot at a championship, that’s awesome.”

Prior comes off as a realist. He knows better than anyone that he’s had a tough go of it, and he knows that the average baseball fan might view him as a has-been whose body never let him fulfill his potential. Maybe that’s true, but Prior doesn’t think the book on his major league career should be closed just yet.

”I know I can compete,” he said. “It’s about just staying healthy and getting out there and putting up innings.”