Mark Webber says Fernando Alonso has "more talent in his little finger" than some of the drivers he was battling in 2015.
Honda's struggles for performance and reliability last year saw McLaren endure its worst season since 1980. The Honda power unit was brutally exposed on straights, with deployment issues meaning McLaren lacked upwards of 160BHP and often saw Alonso and team-mate Jenson Button easily picked off by cars behind.
Before his infamous "GP2 engine" radio rant in Japan last year, Alonso complained his power unit was "embarrassing" after being passed by Sauber's Marcus Ericsson early in the race. Webber says the Honda situation was always bound to frustrate a driver of Alonso's calibre.
"He just wants to be at the front maximising his potential," Webber is quoted as saying by PA Sport. "Last year, when he was fighting with some of the guys he was fighting with, Fernando has got more talent in his little finger.
"If you are knocking around with those guys, week in week out, it wears you down. That is a question for him and his drive and tenacity and determination. It is about that middle step on the podium for him. Would he love to parachute himself into a Mercedes? Of course he would."
Webber says reliability problems are the most frustrating part of a driver's job, especially in the latter stages of their career.
"There is nothing worse than having non-finishes. It is horrible for a driver to go through that effort, and you don't even see the chequered flag. So, they have got to get that reliability going, and that will be important for the drivers and to keep both their boys in the future. If they are operationally poor, in terms of reliability, it is a pain in the arse at that point in your career. It's horrible."