England international Gordon faced some criticism after illness meant he started Newcastle's UEFA Champions League draw with Barcelona in midweek on the bench, and he issued an emphatic response.

Gordon put Newcastle ahead in the 18th minute, slotting home after Tino Livramento made it look all too easy to cut through Chelsea's defence, sliding a pass into the path of Joe Willock.

Newcastle felt it should have had a penalty when Malick Thiaw went down under pressure from Reece James, who signed a new contract with Chelsea this week, at a corner.

Liam Rosenior replaced Malo Gusto with Liam Delap at half-time as he looked to help his team force its way back into the game.

Cole Palmer had an appeal for a penalty after being caught by Nick Woltemade turned down, while Marc Cucurella's claim that Sven Botman handled his cross was ignored.

Delap skied a glorious chance with 15 minutes remaining and then steered a header narrowly wide, but it was James who went closest to finding an equaliser.

The Chelsea captain saw his brilliant 25-yard free-kick hit the foot of the post and go behind, leaving Chelsea in danger of dropping to sixth in the table if results go against them on Monday (AEDT).

"It's frustrating, the first 15-20 minutes we dominate the game," Rosenior said.  

"Waves of attack. We switch off on the press and it's a really poor goal. It gives them a goal and something to hold on to.

"The rest of the game was attack versus defence and credit to Eddie [Howe] and Newcastle. They sat back and we didn't have the freshness in attack.

"There was an issue with the cover and understanding on the press. That'll come. It's new in terms of what we're asking the players to do, but we're talking about one moment when the rest of the game our press was very good.

"The problem with us wasn't without the ball. The problem was the final third. We got there many times. Created chances but weren't ruthless enough to take them."

Only three of Chelsea's 22 shots were on target, and Rosenior felt the trend of not capitalising on key moments has been an issue all season.

"Football's really amazing, isn't it?" the Chelsea boss said.

"At the moment, in the last two games, we haven't managed to take advantage of the moments or the margins.

"We need to assess where the players are at and we need to pick a team that can go out against PSG and play with real intensity."

Chelsea faces PSG in the second leg of its UEFA Champions League Round of 16 tie on Wednesday (AEDT), trailing 5-2 on aggregate, before it heads to Everton in the Premier League next weekend.