Danny McGrain believes that guiding Celtic to a Champions League victory over Barcelona was reason enough on its own for Neil Lennon to deserve to win the PFA Scotland Manager of the Year award.

Allan Johnston, of Queen of the South, received the accolade instead, and McGrain remains baffled by the decision.

He is respectful of Johnston's work this season, and praises the young manager for leading his side so emphatically to the Irn-Bru Second Division title and Ramsdens Cup final win, but McGrain is adamant that the award ought to have been made to Lennon, whose Celtic team won the Clydesdale Bank Premier League title last month. The Celtic first-team coach attended the PFA Scotland awards with Lennon, and is convinced his colleague was worthy of being recognised for his achievements.

"I was disappointed for him," McGrain said. "It's just not right. The guy at Queen of the South has done a great job. But if it had been any team in England who beat Barcelona in the Champions League, the manager would have got a knighthood for it. Neil didn't even get the PFA award. He has got to be the manager of the year."

Lennon is among the leading candidates to replace David Moyes as Everton manager, although Roberto Martinez is still currently the bookmakers' favourite. Although Lennon has an emotional attachment to Celtic, and will again have an opportunity to try to guide the club into the Champions League group stages next season, he is also ambitious to try to prove himself in England.

McGrain, though, believes that while the Celtic manager would have a difficult decision to make should Everton wish to speak to him about their vacancy, the sheer size of Celtic, and the prizes that can be won in Glasgow, will be tough to walk away from. "Everton are not as big as Manchester United, Chelsea, Arsenal, Tottenham Hotspur," McGrain said. "Would he want to pursue chasing these four clubs or would you rather be at the top of the league, winning the league championship?"

McGrain was speaking at the launch of this year's search for Scottish Football Hall of Fame inductees, and he believes Lennon is worthy of inclusion himself, since he has won titles and cups during his 10 years at Celtic, as a player and now as a manager. Brian Laudrup, Henrik Larsson and Terry Butcher are not Scots but have all been inducted for their services to Scottish football, and Lennon deserves the same recognition according to McGrain.

"Neil was a very good player," the Celtic coach said. "I try and do the Neil Lennon role in charity games now and I just can't do it – although I play at the pace he played at. I wouldn't be against Neil being in the Hall of Fame. He deserves to have his name up there."

Georgios Samaras also hopes that Lennon's name remains on the door to the manager's office at Parkhead, with the Celtic striker confident that his side can improve on this season's achievements if they can retain their manager and the crux of the playing squad for next year.

Amid speculation over Lennon's future, players including Gary Hooper, Victor Wanyama and Fraser Forster are expected to be the subject of sustained interest from Barclays Premier League clubs this summer. Samaras, though, believes a squad which achieved so much this season can do better still if all the key components remain in place.

"I really believe in this team," said the Greek. "We have a lot of young players and they can be really good players in Britain. They can play at a high level and if we stay the same team with the same manager, next season can be even better than this season. [The manager] and players are all key to our success.

"This year we've won the league again but the Champions League made people see us from a different angle maybe. Other clubs will come and see players, for sure. And teams will come to the see the manager, but what decisions they make are things I cannot answer."