Everton were easily beaten by Chelsea after a legless performance saw them go down 2-0.
With a match away against Manchester City followed by a Europa League trip to Slovakia to face Ružomberok, it was almost inevitable that Everton would struggle in this fixture.
With the lack of options in his squad, Koeman spoke about his desire to bring in a number of new faces before the window closes.
Speaking after his side's loss, he said: "We need at least two more players, to get numbers up but the most important is to have a striker and one more player because that's what we need," he told a post-match press conference.
"If you look to all the squads of the big teams, they have so many options and if we get everybody back like Seamus Coleman, Morgan Schneiderlin, Yannick Bolasie, Davy Klassen, Ross Barkley and the rest, then you're talking about six or seven first team players."
"I'm always confident because we did some good business but everybody knows and the board knows the importance of those two signings."
Koeman gave very little away in regards to Chelsea striker Diego Costa, who has been the cause of a lot of speculation over the past few weeks.
"I don't know [about Costa]. We are looking at players who are available and if we sign somebody, it is somebody who makes the team better," the Dutchman added.
As for the game itself, Koeman has the following to say via the club's official site:
“I am disappointed about the first half because our ball possession was poor,” he said. “That cost us the second goal, at least. We had spaces to play but we didn’t. We did not have enough movement to give options to the player on the ball.
''You know how Chelsea start and how they press; you need to be at your best to get a result and we weren’t. The second half was much better. Much more control and better organisation, but it was difficult still. We lost it in the first half and not in the second.
“I’m defending my players - they did everything. It wasn’t good enough in the first half, but I’m proud how they fought until the last second to at least be a team on the pitch. It was really difficult and really hot.
“Chelsea hadn’t played in the week and we had a really tough week. Reaching the group stage of the Europa League was what we wanted and one point out of City and Chelsea away games is not bad.”