Union-Sounders Preview

Behind three strong defenders and a red-hot goalkeeper, the defensive-minded Philadelphia Union have emerged as one of the biggest surprises in MLS.

That doesn't bode well for the offensively challenged Seattle Sounders, who are also off to a surprising start but only because they've sunk to last place.

Andre Blake looks to extend his strong start Saturday night when the visiting Union try to stay atop the Eastern Conference with their fourth win in five games.

After finishing second to last in the East while allowing the fifth-most goals (55) in 2015, Philadelphia (3-2-0) gave its defense a makeover in the offseason. Now Keegan Rosenberry and Ken Tribbett are having an impact as rookies, while Richie Marquez has played well since recovering from a groin injury.

Blake has come of age after starting only six matches last season. The third-year goalie totaled 14 saves in his first two games and has been nominated for the league's save of the week award in three of his five performances.

He was tied for sixth in MLS with 19 saves entering the weekend, though he only needed to make two in the Union's 2-1 home win over Orlando City last Friday.

Philadelphia has held opponents to one or no goals in its last four matches, winning three to move into a first-place tie with Montreal in the conference.

"(Blake has) been special, there's no doubt about it," coach Jim Curtin told the team's official website. "We're very happy with his performance."

The Union's much-improved defense will try to add to Seattle's struggles on the attack. Perhaps still recovering from losing leading scorer Obafemi Martins in the offseason, the Sounders (1-3-1) are tied for the second-fewest goals with four and haven't scored more than once in any of their five matches.

As a result, they're sitting at the bottom of the West with four points a season after reaching the conference semifinals.

Star midfielder Clint Dempsey, who was second on the team with 12 goals last season, has one goal and one assist with only six shots on goal.

"In our situation right now, we need all the points we can get," veteran defender Brad Evans said. "When I look at the standings, the first-place team has (one loss) so if we get on the right side of a couple results we'll find ourselves in the top half of the table. So our focus remains, we're at home and we have to get results."

Following an 0-3 start, the Sounders have picked up points in their last two games. They'll try to build on a strong finish Sunday when Chad Marshall scored in extra time - his first goal in nearly two years - to salvage a 1-all draw at Houston.

Seattle has tightened things up in the back, allowing one goal over the past two matches after allowing five in the first three. The club will have to keep a watch on C.J. Sapong and newcomer Chris Pontius, who have five of Philadelphia's seven goals.

Sapong scored in the Union's 1-0 home win in the most recent meeting June 24, but the Sounders have won the past two matchups at CenturyLink Field.