Things already have started popping in the early indoor season, with Bernard Lagat dashing off his eighth victory in the Wanamaker Mile (3 minutes 56.34 seconds) at last week’s Millrose Games. The 35-year-old broke the career mark for Wanamaker wins previously held by Irishman Eamonn Coghlan.

Lagat is in Boston this week, preparing to make more noise in the 5,000 meters at the Reebok Indoor Games tonight (5:30 p.m.) at the Reggie Lewis Center. The Reebok Boston Indoor Games are the second stop of USA Track & Field’s Visa Championship Series.

Lagat is a two-time Olympic medalist who has won two world championships (1,500 and 5,000 in 2007) and owns US records in four events: the indoor 1,500, indoor mile, indoor 3,000, and outdoor 1,500. Stepping up to the 5,000 meters this season, he will make his indoor debut at the distance in Boston, taking on a field that includes a handful of world-class runners.

“After last week, I was really feeling good,’’ Lagat said. “I went home and had some time to relax and take another step in training because I knew I was coming here to face guys who are really tough in the 5K.’’

Lagat believes he can put on a burst of speed at the end of the 5,000 just as he did when he stunned the Millrose crowd with a powerful kick on the 11th (and final) lap to win.

“I think it’s possible to do that, especially if the race goes smooth, never surging in the middle,’’ said Lagat. “I hope it’s going to go like that because I know the guys that are going to be running in there are in good shape.’’

Olympian Galen Rupp, who owns the American record in the indoor 5,000 (13:18.12 in 2009) and was the 2009 US 10,000 champ, has been battling a cold, and was nearly kept home in Oregon by coach Alberto Salazar. But at the last minute, Rupp flew in and is expected to challenge Lagat tonight. Rupp, a 23-year-old Oregon graduate, just made his professional debut last month in the 800 at Albuquerque.

The field is packed with American, Ethiopian, and Kenyan stars, including Ethiopia’s Bekana Daba, who won the Tyson Invitational last year in 13:17.89 when Rupp set the American record to place second.

Anna Pierce, formerly Willard, is one of those runners looking to take a few chances this year. The native of Greenwood, Maine, was an 2008 Olympian in the 3,000 steeplechase, and No. 2-ranked US runner in the 800 in 2009, will run the 1,000 in Boston in the first competition of her indoor season. It’s a strong field, which could push Pierce near the American record of 2:34.19, set by Jen Toomey in 2004.

“It’s hard to tell what your fitness level is, especially in your first race of the indoor season,’’ Pierce said. “We’ve had some really great workouts the last couple of weeks.’’

Morgan Uceny, Pierce’s new training partner was injured last year but Pierce said, “she’s kicking my butt up in Mammoth’’ in training sessions - and Uceny, too, will run the 1,000 tonight. Also lining up is Erin Donohue, a 2008 Olympian in the 1,500, who won the women’s mile at the New Balance Games in New York Jan. 23 with the world’s fastest time this year (4:28.92).

Pierce, whose versatility has made her dangerous at distances from 800 to 3,000, thinks less about setting records as the start time approaches.

“As you get closer to the race, I think it’s important for me just to focus on racing, because that’s what I love to do,’’ said Pierce. “If I think of it as a time trial and go for a record, I think I get lost. I need to focus on what I’m good at and that’s competing.’’

Another risk taker is Nick Willis, the bronze medalist in the 1,500 in Beijing, who was recently bumped up to silver medalist after Bahrain’s Rashid Ramzi was caught doping and relieved of his gold. Kenyan Asbel Kiprop was officially awarded the gold, and Willis, the silver.

“The coolest thing about it all is there’s absolutely no reason for me not to take every risk necessary - calculated risks,’’ said Willis, a 26-year-old New Zealander. “The only way for me to improve from the silver is to go for the gold. There is a huge freedom in that.’’

Willis won the mile here in 2009 (3:53.54) but then missed most of the season after hip surgery in April.

“I’m surprisingly sharp right now,’’ he said. “My coach and I are extremely excited to test on the actual track after a year away to see what I can do, see what this fitness correlates to in terms of time.’’

If there’s one runner tonight who faces little risk, it’s Tirunesh Dibaba of Ethiopia, who has been almost unbeatable the last few years. Though only 24, she is the first runner, man or woman, to claim titles in the 5,000 and 10,000 at the World Championships in 2009, after winning the same events at the 2008 Olympics. She has twice set world records (2005, 2007) in the 5,000 in Boston, and she’s back for more. While she still owns the outdoor world record at 14:11, she lost her world indoor record to Meseret Defar, who ran a 14:24.37 in Stockholm in 2009.

“I have prepared well for this race,’’ she said, through interpreter Elias Kebede. “I have run so many times in Boston. The crowd is unbelievable. I hope we will have that atmosphere.’’