Stoke City v West Ham: Allardyce sweating on Sakho's fitness
Sakho has made an explosive start to life in English football and scored seven goals in eight appearances, with six of those coming in the league.
That West Ham have beaten in recent weeks the sides who finished in the top two last season – champions Manchester City and runners-up Liverpool - is down to a new-look attack deployed by Sam Allardyce, of which Sakho is integral.
Allardyce has spoken glowingly about the "buzz" around the club created by an impressive start to 2014-15, but a shoulder injury could see Sakho sidelined at the Britannia Stadium this Saturday.
"It's 50-50 at the moment and we might even wait until Saturday morning," said Allardyce when quizzed on the chances of Sakho facing Stoke.
Three successive wins, including a 2-1 victory over City last weekend, leave West Ham fourth after nine games.
Allardyce has revolutionised the squad at Upton Park, with the addition of strike duo Enner Valencia and Sakho bringing much-needed pace in attack.
While Sakho's absence would be a blow for West Ham, Allardyce thinks the positive atmosphere in the dressing room is an invaluable assett.
"I've sensed the joy and the goodwill feeling around the camp," he said on Thursday.
"There's a buzz around training which is always good to see.
"But the players now need to maintain and build on their performances.
"We need to make sure we are mentally prepared for the game against Stoke City. It's very easy to lose after a big result like the one against Manchester City so I need to make sure the players are guarded against that."
West Ham are expected to welcome back James Tomkins and Matthew Jarvis after recent injury spells, but Andy Carroll is not yet ready to return as he recovers from an ankle problem.
Hosts Stoke won both games between the teams last season, but have started the new campaign inconsistently and sit in mid-table.
Wednesday's League Cup exit to Southampton was their third defeat in four games in all competitions.
Striker Mame Biram Diouf was on target in the fourth-round tie and is keen to build on that this weekend.
"It was good to score my first goal at home, so personally I will keep working hard to hopefully get more throughout the season," he told the club's official website.
"We will keep our heads up because we were a lot better in the second half and we need to take that performance into Saturday's game against West Ham."
Manager Mark Hughes will be without the services of Phil Bardsley and Peter Crouch through suspension, while Robert Huth (calf), Glenn Whelan (broken leg) and Peter Odemwingie (knee) are long-term absentees.