Chelsea goalkeeper Petr Cech still has his best years to come claims Jens Lehmann

Arsenal cult hero Jens Lehmann has entered the debate over Chelsea's current goalkeeping conundrum, claiming Petr Cech still has the best years of his illustrious career to come and Thibaut Courtois has to prove that he is up to the standard of his senior rival when it comes to tight matches.

Courtois, who returned to Stamford Bridge in the summer of 2014 after a highly successful three-year stint on loan at La Liga champions Atletico Madrid that saw him cement a deserved reputation as one of European football's most promising young talents, initially looked to have won the battle to become Jose Mourinho's first-choice option between the posts after starting and impressing in both the Premier League and Champions League.

While the Belgium international has returned to the line-up in recent weeks, he was replaced by Cech for the clash with Everton on 11 February amid suggestions from Mourinho that Courtois may have been struggling somewhat with the mental demands associated with playing so many consecutive fixtures without a break.

Cech drew plaudits for two impressive saves during the visit of Roberto Martinez's underperforming side and Lehmann believes the 32-year-old still has a lot to give as he enters what should be his most satisfying years as a goalkeeper.

Talented Courtois has lots to learn from Cech

"Courtois is probably the best [young] talent around and he has done really great so far, but in tight games he still has to prove he is up to the challenge of what Petr Cech has done," the former Arsenal favourite, who retired from professional football in 2011 following a short second stint at the Emirates Stadium, told Talksport.

"He [Cech] is getting to the best age for a goalkeeper. I have experienced it myself, when all of a sudden physique comes together with experience. The best years are still ahead of him."

Despite his obvious loyalty to a club with whom he has won three league titles since arriving from Ligue 1 outfit Rennes in 2004 and his usefulness as a competitor and experienced tutor for Courtois, Cech's status as second-choice under Mourinho must give further cause to question just how long he will be content to remain at Chelsea.

Transfer speculation concerning the player has been rife since it was made clear that Courtois would not be spending another season at the Vicente Calderon. And it is perhaps a measure of Cech's enduring professionalism that he opted against seeking pastures new during the recent January transfer window, with Mark Schwarzer instead allowed to depart for struggling Leicester City.

The coming summer may be a different story, though, and even the most critical Chelsea supporter would surely not begrudge Cech the opportunity to continue his career elsewhere.