MANCHESTER, England -- Manchester United's next recruitment drive will focus on signing attacking players, manager Ole Gunnar Solskjaer has confirmed.

Solskjaer sanctioned the departures of Romelu Lukaku and Alexis Sanchez to Inter Milan in the summer without bringing in replacements.

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United now face the prospect of handing 17-year-old Mason Greenwood a first Premier League start of the season against Arsenal on Monday because of injury doubts over Marcus Rashford and Anthony Martial.

The club will aim to do the bulk of their transfer business next summer, but Solskjaer is open to signing a new striker in January.

"We let Alexis and Romelu go, you don't have to be a rocket scientist to see that it's a forward that next time we're going to recruit -- we're looking for some creativity and goals," Solskjaer said.

While United have struggled for goals this season, Lukaku and Sanchez have both had success in the first few weeks of their Inter careers.

Lukaku has scored three goals in six Serie A games, and Sanchez scored twice during the 3-1 win over Sampdoria on Saturday before being sent off for simulation.

Solskjaer was keen to sign a striker in the summer but said he was right to let Lukaku leave even though a replacement could not be found.

"If we had the right one, if it was there, we would have [signed someone]," Solskjaer added.

"It was time for Rom to go. He knows that. He didn't want to be here. What is the point in having players that don't want to be here?

"And it's no point getting players in that you're not 100% sure about.

"When you get players in, you need the right ones that are going to stay here for a longer period, and that's the long-term thinking we have to show.

"I cannot think, 'I need a player because this is my reputation.' No, it's the club.

"There were strikers, but they weren't the ones we wanted. We couldn't get the one we wanted."

United face Arsenal at Old Trafford on Monday having failed to score more than one goal in 17 of their past 20 games dating back to last season.

They have managed just eight goals in six league games this term -- the same number as Aston Villa in 18th -- and Solskjaer admits it is something that will have to change if they want to challenge for a place in the top four.

"We need to score more goals, definitely," Solskjaer said.

"We're working on improving relationships, the patterns, the understanding, and we've started in one end with the foundation, we've done great defensively, but we're not happy with the return going forward."