Ole Gunnar Solskjær refuses to talk about David de Gea’s erratic form

Ole Gunnar Solskjær has refused to confirm whether David de Gea will retain his place when Manchester United host West Ham on Wednesday.

The goalkeeper is again under scrutiny after the error that allowed Mason Mount to score Chelsea’s second goal in the 3-1 FA Cup semi‑final defeat on Sunday. This followed other mistakes from De Gea; Bournemouth’s Junior Stanislas and Tottenham’s Steven Bergwijn beat him with shots that could have been stopped since the Premier League’s restart.

Solskjær was asked to confirm De Gea would start against West Ham. “No, because I don’t want to talk about it,” the manager said. “We stick together as a group. And he’s mentally strong. We’ll stay together and we’ll see the team on Wednesday night.”

Related: De Gea's decline continues as United's FA Cup chance evades his grasp | Jonathan Wilson

If United can avoid defeat at home against West Ham and at Leicester on Sunday they are guaranteed a Champions League berth. Although not speaking about De Gea specifically, Solskjær was clear he would take big decisions when needed regarding selection. “You have to,” he said.

“Every position [in the team] is a big one here so you’ve got to do what is right. We’ll do that on Wednesday, we’ll do that on Sunday.”

Sergio Romero has been United’s regular No 1 in cup competitions yet Solskjær would not be drawn on whether the Argentinian had been disappointed not to face Chelsea. “Everything we talk about is between ourselves. Every player can trust me to keep that confidential,” he said.

Solskjaer drew on a phrase coined by Sir Alex Ferguson to refer to the decisive time of the season. “It is ‘squeaky bum time’,” he said. “I’m looking forward to it and I’m pretty sure the players are as well.”

United are unbeaten in the Premier League since January and Solskjær believes the side’s progress can be traced to the autumn. “You can talk about it all the way back to when we should’ve won against Liverpool [on 20 October]. From then on, we’ve been a very good team and more consistent.”

He switched to 3-5-2 from United’s usual 4-2-3-1 against Chelsea but insisted shape was decided mostly with his team in mind. “It’s 90-10 ourselves but you have to pay respect to any opposition.”

Eric Bailly sustained a head injury on Sunday and is almost certainly unavailable for West Ham and may not feature until the Europa League resumes in August. “Eric stayed in London for all the checks,” Solskjær said. “I didn’t see him yesterday and [he] followed the protocols that are needed. I don’t think he’ll be ready for this game. Everyone is available apart from that.”