DENVER -- Yankees shortstop Eduardo Nunez, who left Sunday's 5-4 loss to the A's in the fifth inning due to tightness in his left rib cage, was unavailable to play Tuesday's series opener against the Rockies but said he felt "so much better" after receiving treatment and resting.
However, manager Joe Girardi is not expecting Nunez to be ready to play on Wednesday.
"That might be a little bit early," Girardi said. "He'd have to go through a series of hoops to get out on the field. But the first thing is you've got to make sure he's pain free just doing simple things."
Namely, hitting a ball off a tee and swinging in soft-toss drills.
With 10 players on the disabled list, the Yankees certainly aren't looking to add Nunez to that group. Were Nunez to be placed on the 15-day DL, the move could be made retroactive to Monday, but that determination isn't imminent.
"You kind of go day by day and see," Girardi said. "And if you really feel it's going to be close to 15 days, then I think you make a move. We're on Day 2, so I think it's too early, but we'll see."
Nunez underwent an MRI exam that revealed no structural damage. He said the inflammation in his rib cage -- while diminished -- is still present.
In Nunez's absence, Jayson Nix, who moved from third base to shortstop when Nunez left Sunday's game, made his fifth start at shortstop on Tuesday.
Nelson back in Colorado after surprise trade
DENVER -- Third baseman Chris Nelson returned to Coors Field on Tuesday, 10 days after the Rockies designated him for assignment and seven days after they traded him to the Yankees for a player to be named or cash considerations.
Nelson, who struck out 19 times in 66 at-bats with Colorado, lost his spot on the Rockies' roster when the club recalled Nolan Arenado from Triple-A Colorado Springs to play regularly. In 21 games with the Rockies before being designated, the 27-year-old Nelson -- taken ninth overall by Colorado in the 2004 First-Year Player Draft -- hit .242 with four RBIs.
"I was definitely surprised," said Nelson, who started and batted seventh on Tuesday against his former club. "[I knew] Arenado's coming up, but I didn't think it would be as soon as it was."
Bill Geivett, the Rockies' senior vice president of Major League operations, called Nelson with the news that he had been traded to the Yankees. Nelson grew up a Yankees fan in the Atlanta area.
"I was happy just to be picked up," Nelson said. "At that point, I was extremely happy. Being a fan of the Yankees, it's kind of cool to be here."
Nelson isn't wondering how long he'll stay with the Yankees, whose slew of players on the disabled list includes corner infielder Kevin Youkilis (lumbar spine sprain), third baseman Alex Rodriguez (left hip surgery) and shortstop Derek Jeter (left ankle surgery). The latter two are not expected back before the All-Star break.
"Like with the Rockies, I wasn't thinking about Nolan coming up," Nelson said, "or A-Rod or Derek Jeter coming back. You can't think about that stuff. The game's tough enough; you can't be thinking about everything else."
• Arenado, Yankees catcher Austin Romine and Mike Gonzalez -- their coach at El Toro High School in Lake Forest, Calif. -- had dinner on Monday night. Romine, who was two years ahead of Arenado in high school, said of the third baseman, "I'm excited to see him play" and that it should be memorable for Gonzalez to see two of his former players in the Major Leagues.
• Yankees right-handed reliever David Robertson said after throwing that his left hamstring felt fine and that he hoped to pitch on Tuesday night. He had tightness in the back of the hamstring, where it meets the knee.
• Yankees infielder Jayson Nix returned to Coors Field for the first time as a visiting player on Tuesday and singled in his first at-bat. He began his career in the Rockies organization -- Colorado took him 44th overall in the 2001 Draft -- and played 22 games for the Rox at the outset of '08 before being optioned to Triple-A Colorado Springs. After that season, Nix moved on to the White Sox, Indians and Blue Jays but didn't play at Coors Field until returning as a member of the Yankees.
• Girardi and first-year Rockies manager Walt Weiss were Colorado teammates in 1994 and '95. Girardi said, "I always thought Walt would make a great manager. He definitely knew the game. It was just a question of what he wanted to do with his life after baseball. I think it's a great opportunity for him, and I think he's doing a great job."
• With their series at Coors Field, the Yankees began their first Interleague series this season at a National League ballpark.
Asked whether he was worried about his pitchers hitting, Girardi said, "A little bit, just because it's not something they do every day."
As far as any instructions for his hurlers on the basepaths, Girardi said, "Be smart. Just please be smart. Go station to station."
Jack Etkin is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.