Teams hoping the Boston Red Sox might be willing to part with left-hander Jon Lester are advised to look elsewhere.

Despite his disappointing performance, the Red Sox will not trade Lester, a major league source said Wednesday, further reinforcing the team's decision to push for a playoff spot in 2012.

The Red Sox remain engaged on a number of fronts to add starting pitching, most notably with the Miami Marlins for right-hander Josh Johnson and the Chicago Cubs for right-hander Matt Garza.

But Boston will face stiff competition from a number of contenders. With the Marlins already having traded another front-line pitcher, Anibal Sanchez, to the Detroit Tigers, another major league source said it was unlikely Miami also would move Johnson "unless another team goes crazy.''

"It makes you feel good that you're wanted," Lester said before Wednesday night's game at Arlington, Texas. "That's kind of the whole point of trade inquires is the fact that other teams want you. It's nice, but it's nice to be here and nice to be wanted here.

"I'm sure it's something that goes on every year; it's just a little more publicized this year because of obviously not very good numbers and some other nonsense that was let out, or said earlier this year about being unhappy and all that other stuff.

"When it comes down to the fact of being wanted, it's a good feeling. That's what everybody wants in life and in your job. It gives you that extra confidence that even though I'm not doing what I normally do, people still see the good and want what I've done in the past."

"I'm sure a lot of teams want him," Red Sox pitcher John Lackey said. "It doesn't surprise me at all. There are a lot of teams that would want a guy like that. This is the first time he's ever struggled. It's not that big of a deal to stick behind a guy who's done what he's done. I think it's a no-brainer."

Meanwhile, several clubs have approached the Red Sox about their surplus of outfielders. The Cincinnati Reds and Pittsburgh Pirates both have scouted the Red Sox extensively. Ryan Kalish, Ryan Sweeney and Cody Ross all have attracted varying degrees of interest.

The Red Sox are at .500 with a 49-49 record, four games behind in the wild-card race. In order to win 90 games, the Red Sox would have to go 41-23 the rest of the way, a .641 percentage. Since 1996, 90 wins would not have been sufficient to qualify for the playoffs; the 2000 Mariners and 2011 Rays both qualified with 91 wins, the fewest since the wild-card Orioles won 88 in 1996.

The extra wild card this season changes things a bit, of course. Since 1996 (the start of the wild card era), the team with the fifth-best record in each league (the equivalent of that second wild-card spot) has averaged 89 wins.

What is the likelihood of the Red Sox playing at a 90-win pace? In the past six seasons, only five teams have played at .641 or better over the season's last 64 games, no more than one in any season. In the National League, only four teams have played at .641 or better, none from 2007-2009.

Over the past 10 seasons, the Red Sox have done so twice -- in 2004, when they went 44-20 (.688) to claim a wild-card spot, and in 2005, when they went 41-23 (.641) to claim another wild-card spot.

There are seven teams ahead of the Red Sox in the wild-card race and another, the Blue Jays, tied with them. The two teams in the lead, the Angels and Athletics, would have to play .600 ball the rest of the way to finish with 91 wins.

ESPNBoston.com reporter Joe McDonald contributed to this report from Arlington, Texas.