Four years have passed since Celtic last played in the Champions League group stages, but the tournament is immediately familiar.

They have faced all of their Group G opponents in the competition before, and some of the teams will still contain players from those previous meetings. It is considered the pinnacle of club football, but there is little excuse for Neil Lennon's side being disconcerted.

Celtic were drawn against Benfica when they reached the group stages in 2006 and 2007, and on both occasions they reached the Round of 16. That similarity can be facile, since it is mostly the same teams that contest this tier of the competition, but the nature of the groups is similar. On both those previous occasions, Celtic were essentially contesting second place, since Manchester United, in 2006, and AC Milan, in 2007, were expected to dominate.

Barcelona, who knocked Celtic out in the Round of 16 in 2008, are among the favourites to win the tournament. It is Benfica, who visit Celtic Park tomorrow night, and Spartak Moscow who will challenge Lennon's players for the runners-up position. The latter side was overcome in a two-legged qualifying round tie in 2007, which Celtic won on penalties, and it is worthwhile for the Scottish champions to take heed of these past meetings.

In their last three experiences of the group stages, Celtic were unbeaten at home. Precedents can be misleading, since in 2008 that still wasn't enough for Gordon Strachan's side to avoid finishing bottom against Aalborg, Villarreal and Manchester United, but they also drew two of those three matches at Celtic Park. In 2006 and 2007, Celtic won all of their home games, including famous victories over Manchester United and Milan, and a similar dominance in Glasgow is likely to be required this time around.

"It's important that they are starting with a home game because they have always been fairly strong at Parkhead in the Champions League," said Paul Hartley, the former Celtic midfielder, now managing Alloa Athletic. "That was certainly the case during my time there. The balance of this group is quite similar to ours [in 2007] because you always thought that Milan would be the favourites to win it but second place was wide open. I'm sure Neil will stress to his players the importance of getting off and running because you don't want to be playing catch up in the early stages when your next two games are away from home.

"No disrespect to the SPL, but this will be stepping up a couple of levels to play a better quality of player. But Neil has played at this level himself and has good experience to pass on to his players. The important thing is to not to play the occasion, it's about maintaining concentration and focus. It's okay playing in the SPL week in, week out, but when you go to that next level, can you do well? You grow as a player [in the Champions League] and hopefully the confidence should get higher."

The Champions League was a source of consternation to Lennon in Perth on Saturday. He felt some of his players were too focused on tomorrow's night tie with Benfica, contributing to a meek display in the defeat by St Johnstone. All aspects of the tournament need to be managed, including the setback of missing the injured Georgios Samaras, who has tended to reserve his best performances for European fixtures.

Celtic's defence was particularly vulnerable at the weekend. It has never been a settled area of the team under Lennon, and the quality of the Champions League opponents will demand a higher level of performance and concentration. Minds will be strained by the sheer aptitude of the players being faced. Celtic cannot be cowed by the occasion, but a figure like Scott Brown is typically unfazed by facing esteemed individuals.

"He's still daft as a brush but as a player he has matured," said Hartley, who played alongside Brown in the Champions League for Celtic. "Scott's discipline is a lot better than it was because when he first came into the team he picked up a lot of bookings. Over the last 18 months, that side of him has improved.

"He doesn't dive into silly tackles and doesn't pick up as many bookings, and being made the captain has probably helped him to calm down. He has always been a good player but he has got better as he has got older and the captaincy has been a big factor in that."

Brown can be a driving force, but he won't be overawed. After all, there's no time, for Celtic to become accustomed to the group stages.