The Portuguese right-back returned from a nine-month absence with knee ligament damage against Zorya Luhansk in the Europa League on Thursday.
However, he had to be substituted at half time in Ukraine after complaining of a groin problem.
Foxes boss Brendan Rodgers provided an update on the 27-year-old, and fellow defender Caglar Soyuncu, following his side’s 2-1 win at Sheffield United in the Premier League on Sunday.
“Ricky has a slight, not a serious, issue with his groin, but probably one that will keep him out for 10 days to two weeks,” said Rodgers.
“It was unfortunate. The surface was very slippy and he’s just aggravated his groin, but hopefully it won’t be too long.”
Soyuncu also suffered a groin injury in Ukraine last week on his comeback. The Turkey international’s return from injury lasted just 16 minutes before he had to be replaced.
Rodgers said scans have shown that the recurrence of the groin problem that had sidelined him since October is not as bad as initially feared, but he did not put a time scale on the 24-year-old’s absence.
“Cags, it’s too early for him to come in, but thankfully it’s not as bad as we first thought,” said the Foxes boss.
“He’ll be out with the medical team next week, and we’ll monitor that, but hopefully it won’t be too long.”
Meanwhile, Rodgers was relieved to avoid an unwanted record at Bramall Lane on Sunday, where Jamie Vardy’s 90th-minute strike saw Leicester return to winning ways.
The Foxes were on the brink of a fifth straight match without a victory, which would have equalled the club’s longest streak without a win since Rodgers took charge in February 2019.
“It was very important for us that we won. It might be the longest period since I’ve been here that we haven’t won, but if not it’s certainly felt the longest. We haven’t performed so well (of late),” said Rodgers.
“It is important we are not used to losing. I’m delighted. After a tough week of travel, it’s a fantastic win for us.”
Sunday’s late defeat was a huge body blow for Sheffield United, who now have the ignominy of having made the worst ever start to a Premier League season.
A 10th defeat in 11 matches left Blades boss Chris Wilder visibly hurt, he said: “It’s one of the hardest periods I’ve been through in my managerial career because of my connection to this football club and we just want to get through it.
“Am I being a counsellor as much as a manager? Yes, it seems that way because we are trying to keep spirits high and people positive.
“These players have swum the channel to get this club in the position it is in. So I’m not going to smash them over the head. I support them.”