Jordan Henderson’s hamstring injury is likely to sideline the Reds captain for possibly another fortnight and with Fabinho and Georginio Wijnaldum virtually locked in there appears to be one spot left to fill.
Keita got the nod against West Ham but after beginning brightly he faded quickly and made way for Oxlade-Chamberlain after 57 minutes with the side 2-1 down.
“I watched the game back, and in that game being 2-1 down helped us a little bit because the direction after that, a lot of things were different,” added Klopp.
“I didn’t know it was the first time since Villa, but the boys reacted well and that’s the only thing we have to know.
“Some people used the word complacency, that they saw glimpses of that. I didn’t see that at all.
“It’s a long season and the concentration level can drop from time to time in all teams, in games and between games. How much the boys fight for a result is exceptional.
“There is no fear about anything, but we also don’t take it for granted that there will just be one or two goals up.
“This game (against Watford) will be tough. I said it, 100 per cent. I don’t want people to think we are going to win 6-0. It just will not happen.”