Celtic defender Mikael Lustig feels they are hitting form and fitness at the perfect time as they prepare for some momentous cup ties and respond to a title challenge.

With Celtic and Aberdeen vying for top spot in the Scottish Premiership, Lustig helped his team to a third consecutive win by scoring a double in a 4-0 win over Motherwell on Wednesday night.

The Swede came within inches of a second-half hat-trick when he hit the bar in the closing stages as he marked his comeback from a two-month injury lay-off in some style.

The 28-year-old is looking for more action when Celtic face Ross County in Dingwall on Saturday in their final game before the eagerly-awaited QTS Scottish League Cup semi-final against Rangers.

"Hopefully I can stay fit now but of course we know we have a lot of important games and fun games coming up in February," he said.

"The Rangers game of course is a massive game but also the cup game against Inter Milan is going to be big as well.

"You always want to play in the big games so all the players will want to be part of that."

Aberdeen recently matched Celtic's earlier eight-match winning league run, which has jolted Celtic into action in recent weeks.

And with the likes of James Forrest joining Lustig in overcoming injury, and a rejuvenated Leigh Griffiths regaining his place in the team, the Swede feels they have the resources to meet the demands of competing on four fronts.

"We need to be focused on every game now," Lustig said. "Aberdeen have done really well and if they keep winning we need to win as well.

"We are going to need all the players now and we need to be ready when we are out there."

Celtic have scored eight goals without reply in their three games in 2015 and Lustig believes they are showing they have adapted to the tactics of manager Ronny Deila following a difficult opening few months for the Norwegian boss.

"We can still manage to do things better but we always had a feeling we were heading in the right direction," the Sweden international said. "We are getting there.

"When you change manager, it's another way to play and the best way to get better is to play games.

"You know you are going to have some games where you don't look good and you maybe feel a bit lost, but most of the players know how to play the game now and how to work as a team. I think we will be there soon."