So far, Sakho and Valencia have proven to be a dynamic combination in attack, using pace and great athletic ability to cause problems in the Premier league.
Zarate has impressed in fits and starts, and speculation has recently linked him with an early exit from East London, with clubs in Italy and Spain monitoring his situation.
Andy Carroll has just come back from injury, and with Carlton Cole still on the books, West Ham have a decent set of strikers - but manager Sam Allardyce still wants more.
Speculation continues to link West Ham with a move for Sunderland striker Connor Wickham, with the Hammers having a host of bids rejected for the England Under-21 centre forward this summer.
Wickham, 21, will be out of contract at the end of the season, and West Ham could still make a bid for him in January, with rumours over the futures of Carroll, Cole and Zarate - but how does he compare to West Ham's leading strikers?
|Position||Team||Shots on goal||Shots on target||Goals||Flick ons||Chances Created||Appearances||Mins Played|
|Diafra Sakho||FW||West Ham||27||8||6||23||2||8||648|
|Enner Valencia||FW||West Ham||27||7||3||13||2||10||661|
|Mauro Zárate||FW||West Ham||9||3||2||1||0||5||317|
As ever, the stats only tell a small section of the story, but we can see that Wickham has had as many shots on goal as Sakho in Valencia - but in almost 400 more minutes of action.
The most telling part is that he's only managed five shots on target in 1006 minutes of action - one in every 201 minutes, which is over two whole games.
With just one goal to his name, he sits bottom of that category, with even Zarate - who has played just 317 minutes of football this season - scoring more often.
However, where Wickham's value may be to Allardyce is as an aerial presence. Standing at just over 6ft 2in tall, Wickham is the prototypical Allardyce striker, with more pace than the likes of Carroll.
We can see that he's won 50 flick ons this season, something that Sakho or Valencia would feed off perfectly if he was to arrive at Upton Park.
Wickham's technical ability has been shown this season too, going on a slaloming run against Stoke before setting up Steven Fletcher for an easy tap-in.
Signing Wickham only really makes sense if one of Carroll, Cole or Zarate leave, but the stats are able to show us two key things.
The first is that Wickham is still very raw and learning his trade. He's 21 and hasn't quite learned how to influence the game on a regular basis, whilst the second is that he seems like an ideal striker for Allardyce to mould.
As we near the January transfer window, Sunderland will no doubt be panicking over Wickham's future - and West Ham could well land him for a knockdown fee; but fans should be ready for ups and downs if he does sign.