Hibs announced earlier in the week that the 26-year-old, who joined the McDiarmid Park club from Falkirk in 2008, will move to Leith at the end of the season on a two-year agreement.
Saints boss Lomas, whose side return to action against Motherwell at Fir Park on Saturday following their winter break, took a pragmatic view to the loss of one of his top players.
The Northern Irishman told Press Association Sport: "I knew it was going to happen, that's just the way it is.
"We can't compete with the likes of Hibs and some other SPL clubs for wages, it's as simple as that. Liam has been a great servant to the club and I have no worries about him for the rest of the season. I know his character, he will give it everything and it's because of players like him that St Johnstone have had success in recent seasons, they are all an honest bunch of lads."
Lomas has already lined up a replacement in Richard Brittain, who has signed a pre-contract deal, although the move to recruit the Ross County skipper raised a few eyebrows.
The former West Ham and Manchester City midfielder accused Brittain of diving to get one of his players sent off in Saints' 2-1 win at County in September and branded the 29-year-old a "cheat", which earned Lomas a two-game suspended touchline ban from the Scottish Football Association.
However, he insists those comments were made in the heat of battle. Lomas said: "There is no problem - he has signed hasn't he? That was my opinion on the day. There are always two opinions and that is what makes football the game it is.
"When I played it was a war against the opposition but it was over when we came off the pitch. I know what Richard Brittain will give us, he is a competitor. He has been in the SPL and down the lower leagues so he has had a few setbacks.
"But he has showed the strength of character to fight back and has shown leadership qualities, that's why he is captain of Ross County. He will be a fabulous acquisition."