DENVER — Just like they did in 2007, the Colorado Rockies open the playoffs in Philadelphia as the hottest team in the National League.

Only this time, they might be without the hottest pitcher in baseball.
Lefty Jorge De La Rosa, who went 16-3 after losing his first six decisions, will test his tight left groin in a bullpen session Tuesday in Philadelphia in an experiment that will go a long way toward determining the rest of the Rockies’ rotation.
De La Rosa reported feeling better Monday but everything hinges on his side session in Philly.
“He was in here at our ballpark earlier today and he was treated. He feels better today,” manager Jim Tracy told The Associated Press on his way to the airport Monday. “The bullpen session tomorrow will tell us whether he has a chance to be a part of the divisional series.”
De La Rosa, whose 16 wins since June 1 leads the majors, left his last start Saturday night after hurting himself on his 40th pitch, ending his duel with Los Angeles Dodgers left-hander Clayton Kershaw with the NL West title on the line.
De La Rosa’s injury left the Rockies’ rotation in limbo.
Tracy is committing only to young ace Ubaldo Jimenez, with his darting 100 mph fastball, starting Game 1 on Wednesday at Citizens Bank Park.
Aaron Cook, who has yielded one run in 13 innings since returning from a sore shoulder that sidelined him for more than a month, will likely get the nod for Game 2 on Thursday, with Jason Hammel or Jason Marquis starting Game 3 in Denver if De La Rosa can’t.
At least the Rockies have depth — they’re the only team in the majors to have all five starters reach double-digit wins.
And they have a brilliant bullpen led by Huston Street, who came to Colorado in the Matt Holliday trade last winter and has saved 35 games in 37 chances.
However, their eighth-inning setup man, lefty Franklin Morales, is coming off a seventh-inning blowup Saturday night in which he was charged with all five runs in the Dodgers’ division-clinching win.
Tracy is sticking by his lanky left-hander.
“We’re not here, we’re not in this position without Franklin Morales,” Tracy insisted. “He’s a young kid, and there’s going to be peaks and valleys with a young kid. When he’s throwing the ball well, good luck. He’s given us more than just a glimpse of that. I mean, we lost Huston Street for three-plus weeks, and we gave the ball to that kid in the ninth inning, and he got six saves.”
The Rockies finished a franchise-best 92-70, including 74-42 after Tracy replaced Clint Hurdle as manager on May 29.
Colorado owns the second-best record in the majors at 72-38 since June 4, just behind the New York Yankees (72-37).
On this trip to the playoffs, they’re riding a four-month wave of good baseball rather than a three-week hot streak like in 2007, when they broomed the Phillies during their unfathomable 21-1 run-up to the World Series.
“I think we were more consistent this year,” Troy Tulowitzki said. “In ’07, we made a run at the end that no one had ever seen before, and we just appeared in the playoffs. But this year we’re a better team all the way through.”
Colorado went 2-4 against the Phillies this year, but three of those games were in April and three in early August.
“We haven’t seen them for about two months, so obviously, I think we’re a different team than they faced before,” Ryan Spilborghs said. “We’ve been playing good ball since June. I like the matchup because we beat them two years ago and now they’re the world champs, so it’ll be fun to get a chance to run at them again.
“They’ve got a lot of left-handed starters, which has kind of been our Achilles’ heel this season. But ... we’re just going to come with the best we’ve got, have quality at-bats and see what happens.”
The Rockies are 27-26 when facing left-handed starters this season, and they’re bracing for lefties Cliff Lee, Cole Hamels and maybe rookie J.A. Happ in the first three games.
Colorado’s edge could be its bullpen.
Phillies manager Charlie Manuel has to decide between Ryan Madson or Brad Lidge as his closer, and if he wants to use Happ as a starter or a reliever. Lidge has blown 11 saves after going 48-for-48 last year, and Madson is 10-for-16 in save chances.
“In order to find out exactly how good their bullpen is, obviously we have to get some traffic and get some hits at the right time to knock some guys in and force some decision-making,” Tracy said.
Street likes the Rockies’ chances regardless.
“You’re playing the defending world champions, a team that’s got a lot of confidence and a team that knows how to win in these situations,” Street said. “But we’re coming in playing good baseball right now.”
They’ve been playing good baseball since Tracy took over, his style allowing the team to thrive on the field and build chemistry in the clubhouse.
“Trace enabled our starters to go deeper into games, which in turn put a little less pressure on the bullpen and kind of let everybody down there settle into a role where they knew they were pitching the seventh, eighth or ninth inning,” pitcher Josh Fogg explained. “That’s kept the bullpen fresh and given the offense a chance to either catch up or build on a lead.”
Tulowitzki thrived as much as anyone under Tracy’s tutelage, going from a slumping player who was crouched too low in the batter’s box to one who stands upright, allowing his 6-foot-3 frame to provide leverage for power and also a better wheel house for average.
Now, he’s one of the top cleanup hitters in the game.
“I don’t know what went wrong in L.A. or what exactly happened (when he got fired from the Dodgers in 2005), but I’m glad it happened, I’ll tell you that,” Tulowitzki said. “We have a great manager and someone that I hope to get to spend many years of my career playing for.”