Union sign goalkeeper Oka Nikolov from Eintracht Frankfurt

For the first time since Faryd Mondragón left PPL Park, the Philadelphia Union are set for a true competition at goalkeeper.

The Union announced Wednesday morning that they have signed Oka Nikolov, a 39-year-old who has spent all 19 years of his professional career at German club Eintracht Frankfurt.

The native of Germany played in 229 Bundesliga games and 34 German Cup games for Frankfurt. He holds dual citizenship in Macedonia, and has made five appearances for Macedonia's national team.

In part due to strong performances by Nikolov, Eintracht finished in sixth place in the Bundesliga this past season. That was good enough to get the team a spot in the 2013-14 Europa League.

"Throughout my career an opportunity to move to America and expand my horizons was always a dream of mine, and one which I hope to fulfill now," Nikolov said in a statement issued by Frankfurt on Tuesday.

Philly.com first broke the news that the Union were in talks with Nikolov on Tuesday, and it didn't take long for a deal to be completed.

"We're really excited that we have our first summer signing in Oka," Hackworth said at his weekly press conference on Wednesday. "He is coming here to really be a mentor for our young goalkeepers. Both Zac [MacMath, the current starter] and Chris [Konopka] are two guys that we believe very strongly in, but it's going to help both those guys to have someone of Oka's experience to push those two players - not only in training, but in playing time."

Hackworth insisted that "Zac is absolutely, 100 percent, still the starter - no question about that." But he also indicated that "if Oka plays so well and he deserves it, he's going to play."

"[Nikolov] has to prove himself," Hackworth said. "We know what his value is - his leadership and experience - but we aren't bringing him just to be a good guy in the locker room. We want him to push things."

Hackworth added that Nikolov is "going to have to do a whole lot, in our coaching staff's opinion, to unseat our whole feeling about the potential of Zac MacMath and how good he is and how good he can be, given the proper pressure - even from within the team - to improve and make himself better."

Since the start of 2012, MacMath has played every minute of all but two league games and one U.S. Open Cup game. The 21-year-old has had definite highs and lows, excelling as a shot-stopper but struggling at times with crosses and set pieces.

Hackworth admitted that MacMath's confidence is "certainly a concern," but he added that "Zac knows the situation, he knows he's still number one, he knows that we still believe in him and trust in him."

"If I fly [Nikolov] in and the next day I start him, yeah, if I were Zac, I'd be pretty rattled about it," Hackworth said. "But that's not the way we will approach this at all."

MacMath hasn't had a teammate capable of challenging him for the starting job since Mondragón returned to his native Colombia after the 2011 season. Backup Chris Konopka has only seen time in friendly games.

Indeed, there are some similarities to Nikolov's arrival and that of Mondragón. Both men came to the Union from German clubs, and brought a lot of experience on their résumés.

But as Hackworth pointed out, the differences outweigh the similarities.

"We have chosen to invest in young goalkeepers, and we have Zac who's in his second year of being a full-time starter," Hackworth said. "Faryd was coming here to be the number one quite clearly, and Oka's coming here for a different reason."

In the end, Hackworth said, "I'm going to put the best players on the field, and in that regard I wouldn't bring a guy here just to be a practice player in most situations."

Regardless of who starts, bringing in Nikolov will solve a practical problem for the Union: they'll finally have the standard three goalkeepers on their roster. They've only had two so far this season. That may not seem like much of a problem on game days, but if MacMath or Konopka had gotten hurt it would have been a big deal.

Hackworth acknowledged that the Union have been pursuing Nikolov since the offseason, and that their mutual interest is a reason why the Union have only carried two goalkeepers this year.

Nikolov won't be eligible to take the field for the Union until Major League Soccer's summer transfer window opens on July 9. The first game he could play in is the July 12 home game against Chivas USA.

The Union have four league games between now and then, including Sunday's showdown with the rival New York Red Bulls at PPL Park (5:00 p.m., ESPN).

On the financial side of things, the terms of Nikolov's were not disclosed, as per MLS policy. It is known, though, that he comes to Philadelphia as a free agent. Eintracht chief executive officer Heribert Bruchhagen told the Associated Press on Tuesday that Nikolov's contract with the German Bundesliga club has been annulled with immediate effect at Nikolov's request.

That means the Union won't have to pay a transfer fee.

Watch full video of Union manager John Hackworth's weekly press conference below.