Derk Boerrigter is a doubt for Celtic's Champions League Group H clash with Barcelona at Parkhead on Tuesday night.

The Hoops wide-man sustained a knock against Morton last week and is still struggling with an ankle complaint he picked up against Ross County a few weeks ago and did not train today.

Midfielder Beram Kayal (groin) and winger James Forrest (virus) did train and are available while midfielder Joe Ledley is still out with a groin injury.

Meanwhile, Neil Lennon believes the absence of Lionel Messi from Tuesday night's Champions League clash is a boost for Celtic, but insists it is also "tinged with sadness".

The 26-year-old Argentina forward injured his thigh in a 2-0 Primera Division win over Almeria on Saturday and has been ruled out for between two and three weeks.

Hoops boss Lennon, whose side lost their Group H opener 2-0 to AC Milan at San Siro, said: "It is obviously very good news for us because he is the best player in the world.

"However, it is tinged with sadness because it is always fantastic to see the great players play here in Glasgow.

"We are looking forward to the game, we welcome Barcelona with open arms and we are hoping it is going to be another great occasion."

Neymar is likely to take over Messi's superstar mantle for the evening and become the focus of the Barca attack but Lennon does not believe the two players can be compared.

The former Parkhead skipper said: "It is like comparing a dog with a cat.

"They are two different types, two different players altogether.

"He (Neymar) is wonderfully gifted, quick, predominantly playing on the left-hand side and he has goals in him.

"He is only young and he has a fantastic future but it is far too early to make comparisons to Messi.

"There is only one player currently who could arguably be around the calibre of Messi and that is Cristiano Ronaldo."

Lennon, whose side famously beat the Catalan giants 2-1 at Celtic Park last November on their way to the last 16 of the competition, believes Barca will be instantly recognisable even without their Argentinian superstar.

"Our approach will be the same whether Messi plays or not," said the Northern Irishman.

"Barcelona don't change their system, they don't change their style of play really and 4-3-3 is just what they believe in. It has worked well for them very well over the years.

"It would be fantastic if we could get something out of it like we did last year.

"We didn't really budget for it, as it were, in both the games last year, so if we can get something it will be a huge bonus for us.

"It will be very much at times containment; to limit Barcelona to as few chances as we can and at the same time maximise the opportunities that we get, as we did last year.

"But they are not like any other team. Against Milan, we had our fair share of the ball and had our chances.

"But Barcelona, for me, are a class above in the way they pass the ball, the way they create chances and the pace they have in wider areas, and that is not being disrespectful to Milan.

"I think they have been the best club side in the world for possibly the last 10 years although Bayern Munich look to have taken over that mantle."

Aside from missing Messi, the visitors head into the tie likely to be without defenders Javier Mascherano, Jordi Alba and Carles Puyol.

However, Lennon shrugged off the assertion that Barcelona will be weaker at the back.

He said: "You say that they have defensive problems with injuries but they keep on keeping clean sheets; against Rayo Vallecano, Real Sociedad and Almeria. So, regardless of personnel, they are still defending very well.

"They are unbeaten domestically, they got off to a great start in the group (4-0 win over Ajax). They are a fantastic team.

"They will be one of the favourites to win the trophy. Whether they are better than last year, you won't be able to gauge that until the turn of the year."

Provisional Celtic squad: Forster, Matthews, Lustig, van Dijk, Mulgrew, Ambrose, Izaguirre, Rogic, Pukki, Commons, Forrest, Kayal, Brown, Samaras, Stokes, Boerrigter, Atajic, McGeouch, Balde, Biton, Zaluska.

Celtic v Barcelona - past encounters

Celtic 0 Barcelona 0 (Inter-Cities Fairs Cup, December 2, 1964)

Barcelona travelled to Celtic Park for the first time in 1964 for the second leg of their Fairs Cup second-round tie with a 3-1 lead from the first game in Spain. Goals from Zaldua, Seminario and Rife were countered by a strike by John Hughes. A goalless draw took the visitors through to the next round.

Celtic 1 Barcelona 0 (UEFA Cup, March 11, 2004)

Martin O'Neill's side hosted Barca in the first leg of their UEFA Cup clash in 2004. Alan Thompson scored to give Celtic a lead to take over to the Nou Camp, an advantage that Celtic would retain with a goalless draw.

Hoops keeper Robert Douglas and Barca midfielder Thiago Motta were sent off after a melee in the tunnel at half-time, with rookie goalkeeper David Marshall, 19, taking over. Five minutes into the second half Javier Saviola was also sent packing after a challenge on Thompson.

Celtic 1 Barcelona 3 (Champions League, September 14, 2004)

Celtic hero Henrik Larsson returned to Parkhead in a Barcelona shirt to help shoot down his old club's unbeaten home record in the Champions League. Midfielder Deco gave Barca a deserved lead before Hoops keeper Marshall saved a spot-kick from Ronaldinho.

Chris Sutton levelled on the hour but Ludovic Giuly's deflected shot off Jackie McNamara put the visitors back in front with Larsson sealing Barca's win with eight minutes remaining.

Celtic 2 Barcelona 3 (Champions League, February 20, 2008)

Gordon Strachan was Celtic manager when Barcelona visited the east end of Glasgow on Champions League duty in 2008.

Jan Vennegoor of Hesselink put the home side in front in the 15th minute with a header, only for Lionel Messi to level three minutes later.

Barry Robson restored Celtic's lead before the break but Thierry Henry curled in the leveller after being set up by Ronaldinho before Messi grabbed a wonderful 79th-minute winner.

Celtic 2 Barcelona 1 (Champions League, November 7, 2012)

Celtic memorably beat Barcelona in the group stages of the Champions League last season on their way to the last 16 of the competition.

Neil Lennon's side took the lead in the 21st minute when midfielder Victor Wanyama headed past Victor Valdes from a corner.

The visitors continued to dominate possession but with seven minutes remaining teenage substitute Tony Watt grabbed a sensational second.

Lionel Messi pulled a goal back in injury time but it was too little, too late.