Kielty made his presence felt in Saturday's 14-2 win over the White Sox, going 3-for-5 with a team-best four RBIs.
"I think he's fit in really well," said Red Sox manager Terry Francona. "I think his teammates really like him. Again, I can't sit here and tell you I know him like everybody else but he's come in and he looks like he really likes to play. He's very competitive. He's not scared. He looks like he enjoys this atmosphere. He's a good addition to our ballclub."
Kielty's job is to play against left-handed pitchers. And thus, Kielty was in there on Saturday with Mark Buehrle going for the White Sox.
"This is great," Kielty said. "This is as a good a situation as you could be in. So far, everything has been cool. It's a real laid-back club."
Though it is sometimes hard for a player to feel at ease in new surroundings, the Red Sox, through background checks on Kielty, new that wouldn't be a problem.
"We knew what we were getting with this kid," Francona said. "When it was happening, we knew this would be a good addition."
After spending most of Spring Training and then two months of the regular season on the disabled list with leg woes and then playing for an Oakland team that was in third place in the American League West, Kielty has come into a most enviable situation in Boston, where all eyes are on the pennant race and a possible postseason run.
"Postseason is so much fun," said Kielty, who has been there with the Twins and A's. "Just playing in September games that are meaningful makes a big difference instead of playing when you know your season is done. It's tough to get motivated when you're not in it. All these games right now are big games. It creates a lot more intensity."
Lights out in manager's suite: When the Tigers were mobbing each other at 3:32 a.m. ET following Carlos Guillen's dramatic walk-off homer against the Yankees, you can rest assured that Francona was not among those watching. Particularly not after a day in which his own team had played a day-night doubleheader.
Instead, Francona got a salad to go from the hotel restaurant and was basically asleep before his head hit the pillow.
"I woke up next to the lettuce," Francona said.
Papelbon rested: A benefit beyond simply pounding the White Sox by a combined score of 21-4 in Friday's twin bill? Jonathan Papelbon didn't pitch, leaving the Red Sox with a rested closer for the rest of the weekend.
In fact, Papelbon hasn't pitched since Tuesday.
"You don't see that happen too often," Francona said of not needing his closer in a doubleheader sweep. "That was great. Hopefully we'll play a good game today and we have a lead and we can use him."
Big Papi's pop: Perhaps Friday night's two-homer performance served as a sign that David Ortiz could be on the verge of the true power binge he hasn't had this season.
Ortiz entered Saturday with 23 homers after belting 54 in 2006.
"He swung the bat well," Francona said. "If he hits the ball to center ... being the way he is, he's going to hit a home run to right. He's too good not to. When he starts hitting balls out to center field [like the second homer on Friday], that's a good sign."
Coming up: Right-hander Julian Tavarez (6-9, 5.01 ERA) will finish out this four-game series for the Red Sox when he faces White Sox right-hander Javier Vazquez (11-6, 3.66 ERA) on Sunday afternoon. First pitch is scheduled for 2:05 p.m. ET.