Guus Hiddink has admitted Chelsea could become embroiled in a relegation battle with defeats to Everton and Arsenal in the next two games.
The champions of last season are 14th after 21 games, 12 points off their stated target of fourth place and just six clear of Sunderland, who occupy the final relegation place.
The Blues' predicament prompted Jose Mourinho's departure last month and Hiddink's appointment.
Chelsea are unbeaten in six games since Mourinho left, when they were one point off the drop zone, but the midweek draw with West Brom did little to ease concerns.
"It's reality," Hiddink said. "We were down when we started. We were one point off the relegation line, but now we have a little bit more room to breathe.
"We have two difficult games coming up - Everton, who have a very good away record - and then Arsenal.
"If you don't gather points there, you don't know what the others do. The Premier League can surprise you.
"There are 12 points difference to fourth place, which is Tottenham.
"We all like to look forward and to the top of the table, but also don't be unrealistic - you're six points off the line of relegation. That's also a fact.
"We have to work hard and be very concentrated and gather our points to step up.
"That's why it was a pity that in the 86th minute we got this draw against West Brom, which would've helped us a lot to go up."
Hiddink admits Radamel Falcao needs to seek opportunities to play after his parent club Monaco opted against recalling the striker due to injury.
Monaco vice-president Vadim Vasilyev says the Ligue 1 club explored the possibility of cutting short Falcao's loan at Stamford Bridge, only for a thigh problem to end that prospect.
The Colombia striker joined Chelsea last summer after an unsuccessful loan stint at Manchester United.
But his spell with the Blues has been equally underwhelming, with just one goal and no appearances since October due to a thigh injury. A return date is not known.
"For him it's important to play, to start playing," Hiddink said on Friday.
"If you see his recent path here and also at Man United, not playing, that's difficult for a player.
"He must look for circumstances where he can play. I can understand this remark (from Vasilyev)."
Vasilyev earlier revealed the former Porto and Atletico Madrid striker did return to Monaco last week to be assessed by his parent club.
Vasilyev told RMC Sport: "It's true that we've talked about Falcao on numerous occasions.
"The original idea was that he would return to Monaco to play the second half of the season. He came over and had a medical. Unfortunately, he was injured.
"So we took the decision that it would be better for him to stay with Chelsea. Could he return one day? I won't close the door, that door remains open."