There is no question a new vibe surrounds the Union as they enter their seventh Major League Soccer season. That's good news to the loyal fans since the old vibe had gotten stale.

The last two years have featured consecutive trips to (and losses in) the U.S. Open Cup final. But the deep runs in those tournaments couldn't mask the disappointment during the MLS seasons, especially last year.

The Union, who open on Sunday at F.C. Dallas, have qualified for the postseason just once, and that came in their second season, 2011.

In 2014, they were in the playoff picture late. But last year they fell to 10-17-7 and set a franchise record for losses and goals allowed (55).

After the appointment of Earnie Stewart as sporting director, the Union allowed the former U.S. national team star to revamp their stagnant roster.

In doing so, the Union have become younger and more athletic while also fielding a midfield that is stacked with quality.

Most of all, there appears to be overall depth, and coach Jim Curtin will have serious decisions to make on his starting lineup.

"There is 100 percent more depth this year. That is clear," Curtin said.

Will it be enough to make a run at one of the six MLS Eastern Conference playoff spots?

"I won't say anything this year because I think we talked too much in the past about playoffs," said veteran Sebastien Le Toux, the franchise's all-time leader with 48 goals. "We are excited about what we have, and a key is that we let too many points get away last year."

The Union were 5-9 last season in MLS games decided by one goal.

Stewart has let it be known that, while he won't talk much about it, the postseason is indeed a goal.

"You have to shoot for the highest," he said.

Plenty of new players

It's common for MLS rosters to experience change from one year to another, but the Union have brought in 13 new players as part of their 26-man roster.

One of the keys will be replacing midfielder Cristian Maidana, who tied for second in MLS with 15 assists. While critics suggested that Maidana didn't shoot enough and wore down during games, he was still a productive player with pinpoint accuracy on his passes.

Dutch midfielder Roland Alberg will be one of the midfielders who is expected to punch up the attack.

"He is excellent in restarts, corners, and free kicks and will be getting goals and assists from both," Curtin said. "He is good in keeping possession, a strong player on the ball and somebody we have been very happy with."

During the final week of February, the Union signed 30-year-old Brazilian midfielder Ilsinho, who was with the team throughout training camp.

He and Alberg give the Union two strong attacking midfield options. Also in the midfield is Tranquillo Barnetta, although the three-time Swiss World Cup participant has been slowed by tendinitis in his knee and may not be ready for the opener.

The Union acquired Chris Pontius from D.C. United, and he is expected to provide offense from his outside midfield spot. He also can play up top. Pontius has suffered through some injuries, but he scored 12 goals in 2012 and has been impressive in preseason.

Midfield will no doubt be the strength for the Union. Maurice Edu is returning to the midfield after playing center back for much of the last year and a half. But he isn't expected to be ready for the opener because of a stress reaction in his leg.

Veteran Vincent Nogueira, beginning his third season with the Union, provides another grinder in the midfield.

Le Toux adds even more depth.

Last year's leading scorer, C.J. Sapong, also returns, and he'll be the target forward up top. Sapong had a team-high nine goals and plays a physical style, although he isn't adept at breaking down defenders.

Rookie Fabian Herbers, the No. 6 overall pick in the SuperDraft from Creighton, showed finishing skills in the preseason.

Whether Sapong and Herbers could be paired remains to be seen, but Herbers provides quality depth, and he should get his chance eventually.

Questions on defense

The major questions will be on the defense. Outside backs Ray Gaddis and Fabinho and center back Richie Marquez are returning players who are expected to play prominent roles.

Center back Ken Tribbett, a former Drexel standout originally signed to the Union's USL team, the Bethlehem Steel, earned an MLS contact with his stellar preseason and could also earn playing time.

While the back four were often blamed for defensive lapses, that might have been caused by midfielders not getting back. Either way, the Union didn't have an air-tight defense and often were beaten in the air.

The Union plucked Georgetown defenders Joshua Yaro and Keegan Rosenberry as the Nos. 2 and No. 3 overall selections, respectively, in the MLS SuperDraft.

Yaro brings speed in the middle, although a key will be how much pounding the 5-foot-11, 163-pound center back can take. Rosenberry can be an attacking defender from the outside. He pushed Gaddis during preseason at right back.

Brazilian Anderson Conceicao is also in the center back mix, and he can play on the outside.

Maybe the biggest change will be in goal, where Andre Blake is the Union's undisputed No. 1 keeper. Blake played only seven games his first two years but may be ready to show why he was the overall No. 1 MLS SuperDraft pick in 2014.

mnarducci@phillynews.com

@sjnard