Pawel Brozek has been allowed to end his frustrating loan spell at Celtic, but he did not go quietly.

The Polish internationalist had joined from Trabzonspor, with a clause in the deal affording the Parkhead side the option to make the move permanent.

That is not likely to happen after Brozek made just three appearances – twice as a substitute – and has left early so he can attend a training camp in Turkey for Poland's Euro 2012 squad, ahead of this summer's tournament.

His spell at Celtic was supposed to earn him some competitive action ahead of the championships but instead it only added to what has been a irksome campaign. He had directed his frustration at Neil Lennon, the Celtic manager.

"Things did not work out for me as I would have hoped at Celtic. I don't want to leave and start complaining that the coach didn't play me and he picked other players," said Brozek, who has a year left on his contract with Trabzonspor. "But the facts are Neil Lennon promised something different from what actually happened. I didn't get any opportunities. I've had a terrible season in Trabzon and in Glasgow. Now I am very hungry indeed for success at Euro 2012."

Lennon hopes to recruit another central defender and a striker in the summer, but will also look to offload a number of his fringe players to trim the squad and the wage bill. Mark Wilson, Glenn Loovens, Daniel Majstorovic, Cha Du-Ri, Darren O'Dea, Dominic Cervi and Andre Blackman are all out of contract and likely to leave the club. Greig Spence, who had been on loan at Hamilton Academical this season, has been released, while Lennon has confirmed that Efrain Juarez, who spent time in Spain with Real Zaragoza, will also be allowed to leave if Celtic can recoup some of the £4m paid for the Mexican two years ago.

Lennon will need to make a decision on the rest of the club's loanees. Niall McGinn, who has been at Brentford, will return to Celtic Park with a year remaining on his deal, as will Josh Thompson, who has spent the past two seasons on loan at Rochdale, Peterborough United and Chesterfield.

Daryl Murphy had hoped to make permanent his stay at Ipswich Town, having spent the past season on loan there, before manager Paul Jewell recently admitted they could not afford his wages or a transfer fee. The Irishman is expected to return to Celtic after this summer's European Championships although it seems unlikely Lennon will keep him around for the final year of his contract.

Morten Rasmussen, another forgotten figure, also has a year remaining on his deal – having signed a three-and-a-half year contract in January 2010 – but it is hard to envisage a way back for the Danish striker who has been farmed out to Mainz, Aalborg and Sivasspor in recent seasons. Meanwhile, youth prospects Richie Towell, Lewis Toshney, James Keatings and Paul Slane will all likely return from loan stints to try to force their way into first-team contention.