Y.E. Yang, left, practices on the putting green during the first day of practice for this week’s AT&T National. The South Korean golfer played in the final pairing with champion Rory McIlroy in last year’s U.S. Open at Congressional. (Toni L. Sandys/The Washington Post)

A year ago at this time, Congressional Country Club’s immaculate grounds sat in the early stages of recovery. The U.S. Open had come and gone, the famed Blue Course ravaged both by rain that softened it and by Rory McIlroy, who mastered it. The intermingling Gold Course still hosted full-scale buildings — merchandise tents and corporate hospitality venues, so much infrastructure that it was unplayable until fall.

This is the year after — both for Congressional and the PGA Tour event it regularly hosts, the AT&T National. Monday, as a few dozen pros gathered for the sleepiest part of tournament week — a low-key pro-am and a few practice rounds — Congressional appeared back in its old glory. Its greens, so soft and vulnerable a year ago, had their spring back. The rough, the victim of unseasonably hot temperatures prior to the U.S. Open, appeared thick.

In essence, the golf course seems better for the regular tour event, hosted by Tiger Woods and benefiting his foundation, than it did for Congressional’s third U.S. Open.

“It’s in as good a shape as any time since I’ve been here,” said John Lyberger, the club’s director of golf.

There are some easy-to-point-to reasons, but none is more important than the greens. In July 2009 — just after the last AT&T National here, before the event took a two-year hiatus to suburban Philadelphia — Congressional undertook a complete rebuild of the greens on the Blue Course, replacing poa annua grass with bentgrass, which was likely to be more resilient so it could better endure Washington’s hot summers. The Open, then, took place just 20 months after those greens went in, and they weren’t yet fully mature and thus more susceptible to extreme heat or rain.

That also means the greens are now firmer, conditions that officials from the U.S. Golf Association, which stages the Open, desperately wanted but were unable to get, particularly when extremely warm temperatures preceded the event, putting undue stress on the grass. Several overnight thunderstorms the week of the Open further softened the greens. The course had no defense. And a few greens, in the ensuing months, were damaged.

Since then, Congressional has benefited not only from time but also from ideal weather in the winter and spring. The club also took some steps, including reducing the amount of water put on the course in the spring and limiting play a bit more, that helped it get firmer.

“There’s a number of initiatives that we took to help the greens recover from last year, because they had shown signs of stress after the Open,” said Greg Lamb, a Congressional member who serves as the club’s tournament director for the AT&T National. “So the course is spectacular now.”

All of this means that McIlroy’s winning score, a U.S. Open record for strokes under par (16) and lowest total score (268), likely won’t be matched in this, a regular PGA Tour event. Such a flip-flop seems unusual, because the USGA normally tries to present a course in its most difficult conditions. The PGA Tour, when it comes through for an annual stop, is generally more accommodating.

The winning scores of the three AT&T Nationals here: 13 under (Woods, 2009); 12 under (Anthony Kim, 2008); 9 under (K.J. Choi, 2007).

But there are a couple of subtle, meaningful differences this week. For one, Congressional will play to a par of 71, as it did in last year’s Open. When the AT&T National was staged here from 2007 to ’09, it played as a par 70. The difference: The sixth hole, with a green protected by a pond, has a new back tee that can push it to 555 yards and changes it from a par 4 to a par 5. In addition, the PGA Tour likely will at least occasionally use some of the new back tees at holes such as Nos. 9, 12, 15 and 18 — installed to lengthen Congressional to 7,574 yards, the second-longest course in U.S. Open history.

The down side for golf fans: The field that arrives to take on Congressional won’t closely resemble that which came to play the Open. Then, Woods — out because of injuries to his left knee and Achilles’ tendon — was the only notable absentee. But at least in part because of the AT&T National’s soft spot on the golfing calendar, wedged two weeks after the U.S. Open and three weeks before the British Open, many of the world’s top players aren’t here.

Most of the best Europeans have headed back home, including England’s Luke Donald, Northern Ireland’s McIlroy and England’s Lee Westwood, ranked Nos. 1-3 in the world, respectively. Several established American players who have played here before – Masters champ Bubba Watson, U.S. Open champ Webb Simpson, Players winner Matt Kuchar and young star Rickie Fowler among them — have also opted for a week of rest. That leaves Woods as the clear marquee attraction, but just three other top-20 players in the world are joining him (No. 10 Hunter Mahan, No. 13 Dustin Johnson and No. 16 Adam Scott).

Woods will arrive at Congressional on Tuesday, hosting a news conference and playing his first practice round in the afternoon. Late Monday, Vijay Singh and Y.E. Yang — two former major winners who were in the Open field a year ago, when Yang played with McIlroy in the final group Sunday — spent time on the putting green. For all of them, a different experience awaits.

“We were disappointed that the course played soft,” Lamb said. “We know it wasn’t anything that we did, that it was Mother Nature. But we’re now reaping the benefits of what we had hoped to do last year.”