Novak won the Aus and made the finals of US during the Fed / Nadal era and people are predicting him to start winning some slams. Agassi was a far better fast court baseliner than Novak. He would have definitely racked up a few. However, to match anybody against Nadal, Fed and Sampras, arguably the top 3 greatest players ever, is not really fair to anybody.
Djokovic is far quicker than Agassi and plays much better defense. For that reason he is able to frusterate Federer into errors on his not totally "on" days and able to hang in longer rallies with Nadal. Things that are neccessary vs those two players, especialy as avoiding having to play defense or being moved around against Federer or Nadal is an impossability even if you are Agassi. Djokovic of 2007-2008/2009 also had a much stronger 1st serve than Agassi, he has lost his old serve gradually over time though which is why he is much less of a threat now.
However in reality Djokovic has not been a big slam threat to the Federer/Nadal reign at all. He has only beaten Federer or Nadal twice combined in a slam. I believe the combined Slam head to head now is 2-11. He has made all of 3 slam finals in that time, winning 1 vs Tsonga in the final and losing the other 2 to Federer or Nadal. Agassi's peaks before turning 29 came and went like the sea. Atleast 70% of the time in his 20s he was playing worse than the Djokovic of the last 4 years who has remained a solid top 3 performer, although 94-95 Agassi is obviously much better than Djokovic, and even probably 99, 2001-2002 Agassi.
And while it was an older Agassi keep in mind he went 0-9 vs Federer and Nadal in 2003-2005, even though he was still competitive vs all the other top players. That despite the luxury of all the matches being on hard courts.
The biggest problem Agassi would have had is his chances for slams would have almost been limited exclusively to the Australian Open. Look at the others:
French Open- Not a chance as he would have no hope vs Nadal, and Federer is even clearly superior overall on this surface if something happens to Nadal. And if we are presuming in Sampras's time I guess we still have Muster, Kuerten, and Courier too. Agassi barely managed to eke out 1 French Open as it was, imagine adding Nadal and Federer to the mix on top of that, LOL!.
Wimbledon- Not a chance with Sampras, Federer, and even Nadal so strong. As it was he barely eked out 1 title here, just like the French, so imagine adding Federer and Nadal now.
U.S Open- He couldnt beat Sampras here once in 4 attempts, so add Federer in as well, and his general inconsistency, and he would be hard pressed to have the right series of events come together to even win one.
And at the Australian Open Federer himself is a beast, Nadal might prove to be one with time, and
Sampras was very underrated based on his 0-2 vs Agassi there when not near his best in either match he was still very competitive and one imparticular nearly won. And if we presume Agassi choosing to still not play there until 25 and with the deeper pool of greats he is complicating his situation even more.
