Sam Allardyce believes the departure of his assistant Sammy Lee from England duty can only benefit Bolton.
Lee rejected the offer of becoming the full-time England Under-21 coach under new boss Steve McClaren. Instead, he will concentrate fully on his role as right-hand man to Allardyce at the Reebok Stadium.
Allardyce told the club's website: 'I said when we employed Sammy he would be the most important signing of the season and that has proved to be the case.
'He has made a massive contribution to the club over the past 12 months.
'His experience and coaching credentials has taken us on to another level.
'Now that Sammy has had time to understand how the club works, his efforts will increase over this season.
'We will see him come more into his own as a top-class coach.'
Allardyce believes Lee could have helped McClaren bed in.
'I do think from Sammy's point of view it is disappointing he has lost his position with England,' said the Bolton boss.
'He has made a massive contribution and his experience could have helped Steve McClaren.
'However I do understand Steve's decision that he wants to change things around and bring his own men in.'
Allardyce added: 'I'm very pleased we have one of the best young coaches plying his trade with us.
'It is major coup that he will give 100% of his time to the club.'
Bolton lost for the third time in four pre-season outings as they went down to Recreativo Huelva in a friendly tournament in Spain last night.
Kevin Nolan struck twice to level for Wanderers in the second half of their Colombino Trophy semi-final but a late goal from Jesus Vazquez cost them.
Bolton will now play the losers of the other semi-final between UEFA Cup winners Sevilla and Sporting Lisbon in their next game.
The injury-depleted Trotters fell behind after 23 minutes when Antonio Sanchez de la Calle turned in a rebound after a Vazquez header was cleared off the line by Idan Tal.
Nolan pounced to equalise six minutes into the second half but Recreativo immediately restored their lead as Polish youngster Blazej Augustyn conceded a penalty and De La Calle converted.
Nolan struck again with a 70th-minute free-kick but Vazquez had the final say three minutes from time.