Celtic: Brendan Rodgers refuses to be drawn on strength of Old Firm rivals
Celtic manager Brendan Rodgers says it remains to be seen whether Rangers' spending will enable them to close the gap on the champions.
"We'll see," he said, when asked if there would be more of a challenge from Ibrox this term.
Rodgers declined to elaborate on his previous remarks that Pedro Caixinha outspent him in summer transfer fees.
Rodgers revealed fit-again Dedryck Boyata is in the squad for Wednesday's League Cup quarter-final at Dundee.
"I'll speak about Dundee, but there's nothing more to add [on Rangers]," he said, with the Old Firm meeting at Ibrox on Saturday.
"Time will tell. The league's difficult, you have to be at your best every week to get consistent results.
"The important [game] is always the next one. That's always been the mantra here. I've only thought of Dundee.
"Of course there are some great games on the horizon, but being away doesn't hinder us. If anything, we've scored more goals away from home purely because the home teams have to come out a bit more."
After Wednesday's trip to Dens Park and Saturday's visit to Ibrox, Celtic travel to face Anderlecht in the Champions League in nine days.
The Belgian club sacked their manager Rene Weiler after Anderlecht's 2-2 draw at Kortrijk left them nine points adrift of league leaders Club Brugge.
Rodgers expressed his sympathy for the Swiss manager, and said it was too early to gauge the impact on preparations for the Group B tie, with the two sides expected to be vying for third place and a spot in the Europa League after Christmas.
"I'm always disappointed when any manager loses their job," Rodgers said. "How more or less difficult that makes the game I'm not sure. We'll look at that closer to the time.
"It will depend on who goes in. There's always ways to do your analysis, but it's a bit more difficult. Whoever's in charge, it's a tough game for us."
'It's important we have energy and aggression'
Rodgers is relishing the prospect of three away games in three competitions across nine days, and has no qualms about selecting different players for the different ties.
"If you look at my record here, there's only been once, over the course of two games, where we've kept the same team," the Celtic manager said.
"With the number of games that we play, and the intent that we play with, it's vitally important that we have that energy and aggression.
"We've also got a lot of young players and I can't expect them to play in every game. Sometimes it's about that mental freshness for them as well. We'll look at the opponent, what their strengths are, and we have our way of working. We'll pick the best team to win the game.
"We've got a strong squad for a purpose, because we play so many games and we have a level of performance that we need to aspire to every time that we play."